Bright Tuition Classes

Subject : Che Classification of Elements and Paper Set : 1

Standard : 11 Periodicity in Properties Date : 30-06-2024
Total Mark : 600 Time : 0H:0M

.......................................... Chemistry - Section A (MCQ) ..........................................

(1) Arrange the following elements in increasing order of electronegativity:

N, O, F, C, Si
Choose the correct answer from the options given below: [NEET 2024]

(A) Si < C < O < N < F (B) O < F < N < C < Si (C) F < O < N < C < Si (D) Si < C < N < O < F
(2) Which of the following orders of ionic radii is correctly represented ? [NEET 2014]

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(A) H − > H + > H (B) N a+ > F − > O 2− (C) F − > O 2− > N a+ (D) None of the above

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(3) In which of the following options the order of arrangement does not agree with the variation of property
indicated against it ? [NEET 2016]
(A) I < Br < Cl < F (increasing electron gain enthalpy) (B) Li < N a < K < Rb (increasing metallic radius)
(C) B < C < N < O (increasing first ionisation enthalpy) (D) Both (a) and (c)

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(4) Which one of the following arrangements represents the correct order of least negative to most negative electron
gain enthalpy for C, Ca, Al, F and O ? [NEET 2013]
(A) Al < Ca < O < C < F (B) Al < O < C < Ca < F (C) C < F < O < Al < Ca (D) Ca < Al < C < O < F

electronic configuration? [NEET 2017]

(A) Carbon family, [Rn] 5f 14 6d10 7s2 7p2
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(5) The element Z = 114 has been discovered recently. It will belong to which of the following family/group and

(B) Oxygen family, [Rn] 5f 14 6d10 7s2 7p4

(C) Nitrogen family, [Rn] 5f 14 6d10 7s2 7p6 (D) Halogen family, [Rn] 5f 14 6d10 7s2 7p5
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(6) For the second period elements the correct increasing order of first ionisation enthalpy is [NEET 2019]
(A) Li < Be < B < C < N < O < F < Ne (B) L < B < Be < C < O < N < F < Ne
(C) Li < B < Be < C < N < O < F < Ne (D) Li < Be < B < C < O < N < F < Ne
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(7) Identify the incorrect match :

Name IU P AC Official Name
(a) Unnilunium (i) Mendelevium
(b) Unniltrium (ii) Lawrencium
(c) Unnilhexlum (iii) Seaborglum
(d) Unununnium (iv) Darmstadtium [NEET 2020]
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(A) (d), (iv) (B) (a), (i) (C) (b), (ii) (D) (c), (iii)
(8) The IU P AC name of an element with atomic number 119 is ......... [NEET 2022]

(A) unnilennium (B) unununnium (C) ununoctium (D) ununennium

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(9) Arrange the following elements in increasing order of first ionization enthalpy:
Li, Be, B, C, N
Choose the correct answer from the options given below: [NEET 2024]
Br

(A) Li < B < Be < C < N (B) Li < Be < C < B < N (C) Li < Be < N < B < C (D) Li < Be < B < C < N
(10) The species Ar, K + and Ca2+ contain the same number of electrons. In which order do their radii increase ? [NEET
2015]

(A) Ca2+ < K + < Ar (B) K + < Ar < Ca2+ (C) Ar < K + < Ca2+ (D) Ca2+ < Ar < K +
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(11) The ionic radii (in A) of N 3− , O 2− and F − are respectively : [JEE MAIN 2015]

(A) 1.71, 1.40 and 1.36 (B) 1.71, 1.36 and 1.40 (C) 1.36, 1.40 and 1.71 (D) 1.36, 1.71 and 1.40
(12) Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation
correctly is: (Given v = frequency of X-ray emitted; Z = atomic number) [JEE MAIN 2023]
(A) (B) (C) (D)

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(13) Given below are two statements:
Statement- I: Along the period, the chemical reactivity of the element gradually increases from group 1 to group
18.
Statement - II: The nature of oxides formed by group 1 element is basic while that of group 17 elements is
acidic.In the the light above statements, choose the most appropriate from the questions given below: [JEE MAIN 2024]
(A) Both statement I and Statement II are true. (B) Statement I is true but Statement II is False.
(C) Statement I is false but Statement II is true. (D) Both Statement I and Statement II is false.
3+
(14) The ionic radii of K , Na , Al and Mg
+ + 2+
are in the order: [JEE MAIN 2021]
3+ 3+
(A) Al < Mg2+ < K+ < Na+ (B) K+ < Al < Mg2+ < Na+
3+ 3+
(C) Na+ < K+ < Mg2+ < Al (D) Al < Mg2+ < Na+ < K+
(15) The ionic radii of O2 − F − , N a+ and M g 2+ are in the order : [JEE MAIN 2020]
(A) F − > O 2− > N a+ > M g 2+ (B) M g 2+ > N a+ > F − > O 2−
(C) O2− > F − > M g 2+ > N a+ (D) O2− > F − > N a+ > M g 2+
(16) Which of the following represents the correct order of increasing first ionization enthalpy for Ca, Ba, S, Se and Ar

s
? [JEE MAIN 2013]

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(A) Ca < S < Ba < Se < Ar (B) S < Se < Ca < Ba < Ar
(C) Ba < Ca < Se < S < Ar (D) Ca < Ba < S < Se < Ar
(17) Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in +1 and +3 oxidation states. This
is due to [JEE MAIN 2019]

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(A) inert pair effect (B) diagonal relationship (C) lattice effect (D) lanthanoid contraction
(18) Among the following basic oxide is ..... [JEE MAIN 2022]

(A) SO3 (B) SiO2 (C) CaO (D) Al2 O3

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(19) The statement(s) that are correct about the species O2− , F− , Na+ and Mg2+ .
(A) All are isoelectronic
(B) All have the same nuclear charge
(C) O2− has the largest ionic radii
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(D) Mg2+ has the smallest ionic radii
Choose the most appropriate answer from the options given below : [JEE MAIN 2024]
(A) (B), (C) and (D) only (B) (A), (B), (C) and (D) (C) (C) and (D) only (D) (A), (C) and (D) only
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(20) The IU P AC nomenclature of an element with electronic configuration [Rn]5f 6d 7s2 is. 14 1
[JEE MAIN 2022]

(A) U nnilbium (B) U nnilunium (C) U nnilquadium (D) U nniltrium

(21) For elements B, C, N, Li, Be, O and F the correct order of first ionization enthalpy is [JEE MAIN 2023]
(A) Li < Be < B < C < N < O < F (B) B > Li > Be > C > N > O > F
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(C) Li < B < Be < C < O < N < F (D) Li < Be < B < C < O < N < F
(22) Which one of the following has largest ionic radius? [JEE MAIN 2014]

(A) O22− (B) Li+ (C) B 3+ (D) F −

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(23) Given below are two statements :

Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on
the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement (II) : pπ − pπ bond formation is more prevalent in second period elements over other periods.
Br

In the light of the above statements, choose the most appropriate answer from the options given below : [JEE MAIN
2024]
(A) Both Statement I and Statement II are incorrect (B) Statement I is correct but Statement II is incorrect
(C) Both Statement I and Statement II are correct (D) Statement I is incorrect but Statement II is correct
(24) The first ionization energy (in kJ/mol ) of N a, Mg, Al and Si respectively, are [JEE MAIN 2020]
(A) 496, 737, 577, 786 (B) 786, 737, 577, 496 (C) 496, 577, 737, 786 (D) 496, 577, 786, 737
−
(25) In case of isoelectronic species the size of F , Ne and Na is affected by: [JEE MAIN 2024]
+

(A) Principal quantum number (n) (B) None of the factors because their size is the same
(C) Electron-electron interaction in the outer orbitals (D) Nuclear charge (z)
(26) The element with which of the following outer electron configuration may exhibit the largest number of oxidation
states in its compounds [JEE MAIN 2013]
(A) 3d5 4s2 (B) 3d8 4s2 (C) 3d7 4s2 (D) 3d6 4s2
(27) The electronic configuration with the highest ionization enthalpy is [JEE MAIN 2017]
(A) [N e] 3s2 3p1 (B) [N e] 3s2 3p2 (C) [N e] 3s2 3p3 (D) [Ar] 3d10 4s2 4p3

2
(28) In general, the property (magnitudes only) that shows an opposite trend in comparison to other properties across
a period is [JEE MAIN 2020]
(A) Electronegativity (B) Electron gain enthalpy (C) Ionization enthalpy (D) Atomic radius
(29) Element ′ E ′ belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of
the element, which is just above ′ E ′ in the group is ..... [JEE MAIN 2022]
(A) 3s2 · 3p4 (B) 3d10 · 4s2 , 4p4 (C) 4d10 · 5s2 , 5p4 (D) 2s2 , p4
(30) The electron affinity value are negative for :
A. Be → Be−
B. N → N−
C. O → O2−
D. Na → Na−
−
E. Al → Al
Choose the most appropriate answer from the options given below : [JEE MAIN 2024]

(A) D and E only (B) A, B, D and E only (C) A and D only (D) A, B and C only

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(31) Given below are the oxides:

as
N a2 O, As2 O3 , N2 O, N O and Cl2 O7
Number of amphoteric oxides is ..... . [JEE MAIN 2022]

(A) 0 (B) 1 (C) 2 (D) 3

(32) Which of the following arrangements represents the increasing order ( smallest to largest) of ionic radii of the

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given species O2− , S 2− , N 3− , P 3− ? [JEE MAIN 2014]
(A) O2− < N 3− < S 2− < P 3− (B) O2− < P 3− < N 3− < S 2−
(C) N 3 < O2− < P 3− < S 2− (D) N 3− < S 2− < O2− < P 3−

2014]
(A) 3 Li → 19 K Ionization enthalpy increases
on
(33) Which of the following series correctly represents relations between the elements from X to Y ? X → Y

(B) 9 F → 35 Br Electron gain enthalpy (negative sign)

[JEE MAIN

increases
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(C) 6 C → 32 Ge Atomic radii increases (D) 18 Ar → 54 Xe Noble character increases
(34) The correct order of the first ionization enthalpy is [JEE MAIN 2024]
(A) Al > Ga > Tl (B) Ga > Al > B (C) B > Al > Ga (D) Tl > Ga > Al
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(35) In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical ?
(A) Rb and Cs
(B) N a and K
(C) Ar and Kr
(D) I and At
Choose the correct answer from the options given below. [JEE MAIN 2022]
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(A) (A) and (B) only (B) (B) and (C) only (C) (A) and (C) only (D) (C) and (D) only
(36) Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R : Assertion
A : The first ionisation enthalpy decreases across a period.
Reason R : The increasing nuclear charge outweighs the shielding across the period.
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In the light of the above statements, choose the most appropriate from the options given below: [JEE MAIN 2024]
(A) Both A and R are true and R is the correct explanation of A
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(B) A is true but R is false

(C) A is false but R is true
(D) Both A and R are true but R is N OT the correct explanation of A
(37) The first ionization enthalpies of Be, B, N and O follow the order.... [JEE MAIN 2022]

(A) O < N < B < Be (B) Be < B < N < O (C) B < Be < N < O (D) B < Be < O < N
(38) The element having the highest first ionization enthalpy is [JEE MAIN 2024]
(A) Si (B) Al (C) N (D) C
(39) The correct option with respect to the Pauling electronegativity values of the elements is [JEE MAIN 2019]
(A) T e > Xe (B) Ga > Ge (C) Si > Al (D) P > S
−
(40) The size of the iso-electronic species Cl , Ar and Ca 2+
is affected by [JEE MAIN 2019]
(A) Principal quantum number of valence shell (B) Azimuthal quantum number of valence shell
(C) electron -electron interaction in the outer orbitals (D) nuclear charge

3
(41) The ionic radii of F− and O2− respectively are 1.33 Ao and 1.4 Ao , while the covalent radius of N is 0.74 Ao
The correct statement for the ionic radius of N3− from the following is : [JEE MAIN 2021]
(A) It is bigger than F− and N, but smaller than of O2− (B) It is smaller than O2− and F− , but bigger than of N
(C) It is bigger than O2− and F− (D) It is smaller than F− and N
(42) Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : The first ionization enthalpy of 3d series elements is more than that of group 2 metals
Reason (R) : In 3d series of elements successive filling of d-orbitals takes place.
In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2023]
(A) Both (A) and (R) are true and (R) is the correct explanation of (A)
(B) Both (A) and (R) are true but (R) is not the correct explanation of (A)
(C) (A) is false but (R) is true
(D) (A) is true but (R) is false
(43) Match List−I with List−II.

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List−I List−II
(Oxide) (Nature)

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(A) Cl2 O7 (I) Amphoteric
(B) N a2 O (II) Basic

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(C) Al2 O3 (III) Neutral
(D) N2 O (IV ) Acidic
Choose the correct answer from the options given below [JEE MAIN 2022]
(A) (A) − (IV ), (B) − (III), (C) − (I), (D) − (II)
(C) (A) − (II), (B) − (IV ), (C) − (III), (D) − (I)
on
(B) (A) − (IV ), (B) − (II), (C) − (I), (D) − (III)
(D) (A) − (I), (B) − (II), (C) − (III), (D) − (IV )
(44) The correct sequence of electron gain enthalpy of the elements listed below is
A. Ar B. Br C.F D. S
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Choose the most appropriate from the options given below: [JEE MAIN 2024]
(A) C > B > D > A (B) A > D > B > C (C) A > D > C > B (D) D > C > B > A
(45) In the long form of the periodic table, the valence shell electronic configuration of 5s2 5p4 corresponds to the
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element present in [JEE MAIN 2015]

(A) Group 16 and period 6 (B) Group 17 and period 6 (C) Group 16 and period 5 (D) Group 17 and period 5
(46) The most polar compound among the following is [JEE MAIN 2018]
(A) (C) (D)
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(B)
(47) The third ionization enthalpy is minimum for [JEE MAIN 2020]
(A) F e (B) N i (C) Co (D) M n
Br

(48) These are physical properties of an element

(A) Sublimation enthalpy
(B) Ionisation enthalpy
(C) Hydration enthalpy
(D) Electron gain enthalpy
The total number of above properties that affect the reduction potential is ...... . [JEE MAIN 2021]

(A) 3 (B) 4 (C) 5 (D) 6

(49) Aqueous solution of which salt will not contain ions with the electronic configuration 1s2 2s2 2p6 3s2 3p6 ? [JEE MAIN
2016]

(A) N aF (B) KBr (C) N aCl (D) CaI2

(50) Electron gain enthalpy with negative sign of fluorine is less than that of chlorine due to [JEE MAIN 2013]
(A) High ionization enthalpy of fluorine (B) Smaller size of chlorine atom
(C) Smaller size of fluorine atom (D) Bigger size of 2p orbital of fluorine
(51) The CORRECT order of first ionisation enthalpy is: [JEE MAIN 2021]

(A) Mg < Al < S < P (B) Al < Mg < S < P (C) Mg < Al < P < S (D) Mg < S < Al < P

4
(52) Outermost electronic configurations of four elements A, B, C, D are given below.
3s2 ; 3s2 3p1 ; 3s2 3p3 ; 3s2 3p4
The correct order of first ionization enthalpy for them is. [JEE MAIN 2022]
(A) (A) < (B) < (C) < (D) (B) (B) < (A) < (D) < (C) (C) (B) < (D) < (A) < (C) (D) (B) < (A) < (C) < (D)
(53) Which of the following presents the correct order of second ionization enthalpies of C, N, O and F ? [AIEEE 2012 , JEE
MAIN 2013]

(A) F > O > N > C (B) O > N > F > C (C) C > N > O > F (D) O > F > N > C
(54) The acidic, basic and amphoteric oxides, respectively, are [JEE MAIN 2020]
(A) MgO, Cl2 O, Al2 O3 (B) Cl2 O, CaO, P4 O10 (C) Na2 O, SO3 , Al2 O3 (D) N2 O3 , Li2 O, Al2 O3
′ ′ ′ ′
(55) Consider the following ionization enthalpies of two elements A and B .
Element Ionization enthalpy (kJ/mol)
1st 2nd 3rd
A 899 1757 14847
B 737 1450 7731

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Which of the following statements is correct ? [JEE MAIN 2017]

as
(A) Both A and B belong to group −1 where B ′ comes below ′ A′ .
′ ′ ′ ′ ′

(B) Both ′ A′ and ′ B ′ belong to group −1 where ′ A′ comes below ′ B ′ .

(C) Both ′ A′ and ′ B ′ belong to group −2 where ′ B ′ comes below ′ A′ .

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(D) Both ′ A′ and ′ B ′ belong to group −2 where ′ A′ comes below ′ B ′
(56) In general, the properties that decrease and increase down a group in the periodic table respectively are [JEE MAIN
2019]
(A) atomic radius and electronegativity
(C) electronegativity and atomic radius
on (B) electron gain enthalpy and electronegativity
(D) electronegativity and electron gain enthalpy
(57) The first ionization enthalpy of N a, M g and Si, respectively, are: 496, 737 and 786 kJ mol−1 . The first ionization
enthalpy (kJ mol−1 ) of Al is [JEE MAIN 2022]
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(A) 487 (B) 768 (C) 577 (D) 856
(58) It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power ’ n ’ i.e.
v n of X-rays emitted is plotted against atomic number ’ Z ’, following graph is obtained. The value of ’ n ’ is [JEE MAIN
2023]
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(A) 1 (B) 2 (C) 0.5 (D) 3

(59) The incorrect statement is [JEE MAIN 2022]
Br

(A) The first ionization enthalpy of K is less than that of N a and Li

(B) Xe does not have the lowest first ionization enthalpy in its group
(C) The first ionization enthalpy of element with atomic number 37 is lower than that of the element with atomic
number 38 .
(D) The first ionization enthalpy of Ga is higher than that of the d−block element with atomic number 30.
(60) The following statements concern elements in the periodic table. Which of the following is true ? [JEE MAIN 2016]

(A) For Group 15 elements, the stability of +5 oxidation state increases down the group
(B) Elements of Group 16 have lower ionization enthalpy values compared to those of Group 15 in the
corresponding periods
(C) The Group 13 elements are all metals
(D) All the elements in Group 17 are gases
(61) B has a smaller first ionization enthalpy than Be. Consider the following statements :
(I) It is easier to remove 2p electron than 2s electron

5
 (II) 2p electron of B is more shielded from the nucleus by the inner core of electrons than the 2s electrons of Be.
(III) 2s electron has more penetration power than 2p electron.
(IV ) atomic radius of B is more than Be
(Atomic number B = 5, Be = 4 )
The correct statements are [JEE MAIN 2020]
(A) (I), (II) and (III) (B) (II), (III) and (IV ) (C) (I), (III) and (IV ) (D) (I), (II) and (IV )
(62) Given below are two statements:
Statement I: Fluorine has most negative electron gain enthalpy in its group.
Statement II: Oxygen has least negative electron gain enthalpy in its group.
In the light of the above statements, choose the most appropriate from the options given below. [JEE MAIN 2024]
(A) Both Statement I and Statement II are true (B) Statement I is true but Statement II is false
(C) Both Statement I and Statement II are false (D) Statement I is false but Statement II is true
(63) The metal that has very low melting point and its periodic position is closer to a metalloid is. [JEE MAIN 2022]

(A) Al (B) Ga (C) Se (D) In

(64) Given below are two statements:

s
Statement I : The correct order of first ionization enthalpy values of Li, Na, F and Cl is Na < Li < Cl < F.

as
Statement II : The correct order of negative electron gain enthalpy values of Li, Na, F and Cl is Na < Li < F < Cl
In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2024]
(A) Both Statement I and Statement II are true (B) Both Statement I and Statement II are false

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(C) Statement I is false but Statement II is true (D) Statement I is true but Statement II is false
(65) The IU P AC symbols for the element with atomic number 119 would be: [JEE MAIN 2019]

(A) U un (B) U ue (C) U uh (D) U ub

(66) The 71
(A) 6p
st

(B) 4f
on
electron of an element X with an atomic number of 71 enters into the orbital:
(C) 5d
(67) For N a+ , M g 2+ , F − and O2− ; the correct order of increasing Ionic radii is [JEE MAIN 2018]
[JEE MAIN 2019]

(D) 6s

(A) O2− < F − < N a+ < M g 2+ (B) N a+ < M g 2+ < F − < O 2−

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(C) M g 2+ < N a+ < F − < O 2− (D) M g 2+ < O 2− < N a+ < F −
(68) The difference between electron gain enthalpies will be maximum between: [JEE MAIN 2023]

(A) N e and F (B) N e and Cl (C) Ar and Cl (D) Ar and F

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(69) Which is the correct order of second ionization potential of C, N, O and F in the following ? [JEE MAIN 2013]

(A) O > N > F > C (B) O > F > N > C (C) F > O > N > C (D) C > N > O > F
(70) Match List−I with List−II :

List−I List−II
(Metal Ion) (Group in Qualitative analysis)
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(a) M n2+ (i) Group −III

3+
(ii) Group −IIA
ig

(b) As
(c) Cu 2+
(iii) Group −IV
(d) Al3+ (iv) Group −IIB
Br

Choose the most appropriate answer from the options given below : [JEE MAIN 2021]
(A) (a) − (i), (b) − (ii), (c) − (iii), (d) − (iv) (B) (a) − (iii), (b) − (iv), (c) − (ii), (d) − (i)
(C) (a) − (i), (b) − (iv), (c) − (ii), (d) − (iii) (D) (a) − (iv), (b) − (ii), (c) − (iii), (d) − (i)
(71) The correct order of the atomic radii of C, Cs, Al and S is [JEE MAIN 2019]
(A) C < S < Al < Cs (B) S < C < Cs < Al (C) S < C < Al, Cs (D) C < S < Cs < Al
(72) Which one of the following statements for D.I. Mendeleeff, is incorrect? [JEE MAIN 2021]

(A) At the time, he proposed Periodic Table of elements structure of atom was known.
(B) Element with atomic number 101 is named after him.
(C) He invented accurate barometer.
(D) He authored the textbook − Principles of Chemistry.
(73) The element with Z = 120 (not yet discovered) will be an/a [JEE MAIN 2019]

(A) Inner transition metal (B) Alkaline earth metal (C) Alkali metal (D) Transition metal

6
(74) The correct decreasing order for metallic character is [JEE MAIN 2022]
(A) N a > M g > Be > Si > P (B) P > Si > Be > M g > N a
(C) Si > P > Be > N a > M g (D) Be > N a > M g > Si > P
(75) Consider the following elements.
Which of the following is/are true about A′ , B′ , C′ and D′ ?
A. Order of atomic radii: B′ < A′ < D′ < C′
B. Order of metallic character: B′ < A′ < D′ < C′
C. Size of the element : D′ < C′ < B′ < A′
D. Order of ionic radii : B′+ < A′+ < D′+ < C′+
Choose the correct answer from the options given below : [JEE MAIN 2024]

(A) A only (B) A, B and D only (C) A and B only (D) B, C and D only
(76) Given below are two statements:

s
Statement (I) : The 4f and 5f - series of elements are placed separately in the Periodic table to preserve the
principle of classification.

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Statement (II) :S-block elements can be found in pure form in nature. In the light of the above statements, choose
the most appropriate answer from the options given below : [JEE MAIN 2024]
(A) Statement I is false but Statement II is true (B) Both Statement I and Statement II are true

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(C) Statement I is true but Statement II is false (D) Both Statement I and Statement II are false
(77) Number of elements from the following that CAN N OT form compounds with valencies which match with their
respective group valencies is
B, C, N, S, O, F, P, Al, Si
(A) 7
[JEE MAIN 2024]

(78) Given below are two statements:

(B) 5
on (C) 6 (D) 3

Statement I : The metallic radius of Na is 1.86 A◦ and the ionic radius of Na+ is lesser than 1.86 A◦ .
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Statement II : Ions are always smaller in size than the corresponding elements.
In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2024]
(A) Statement I is correct but Statement II is false (B) Both Statement I and Statement II are true
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(C) Both Statement I and Statement II are false (D) Statement I is incorrect but Statement II is true
5
(79) Identify the element for which electronic configuration in +3 oxidation state is [Ar]3 d : [JEE MAIN 2021]

(A) Ru (B) M n (C) Co (D) Fe

(80) The correct order of increasing ionic radii is .... . [JEE MAIN 2022]

(A) M g 2+ < N a+ < F − < O 2− < N 3− (B) N 3− < O 2− < F − < N a+ < M g 2+
ht

(C) F − < N a+ < O 2− < M g 2+ < N 3− (D) N a+ < F − < M g 2+ < O 2− < N 3−
(81) Among the statements (I − IV ), the correct ones are:
(I) Be has smaller atomic radius compared to M g
ig

(II) Be has higher ionization enthalpy than Al.

(III) Charge/radius ratio of Be is greater than that of Al.
(IV ) Both Be and Al form mainly covalent compounds. [JEE MAIN 2020]
Br

(A) (I), (II) and (IV ) (B) (II), (III) and (IV ) (C) (I), (II) and (III) (D) (I), (III) and (IV )
(82) For electron gain enthalpies of the elements denoted as ∆eg H, the incorrect option is : [JEE MAIN 2023]

(A) ∆eg H(Cl) < ∆eg H(F ) (B) ∆eg H(Se) < ∆eg H(S) (C) ∆eg H(I) < ∆eg H(At) (D) ∆eg H(T e) < ∆eg H (Po)
(83) Three elements X, Y and Z are in the 3rd period of the periodic table. The oxides of X, Y and Z, respectively, are
basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is [JEE MAIN 2020]
(A) Z < Y < X (B) X < Z < Y (C) X < Y < Z (D) Y < X < Z
(84) When the first electron gain enthalpy (∆eg H) of oxygen is −141 kJ/mol, its second electron gain enthalpy is [JEE MAIN
2019]
(A) a more negative value than the first (B) almost the same as that of the first
(C) negative, but less negative than the first (D) a positive value
(85) The atomic number of Unnilunium is........... [JEE MAIN 2020]

(A) 101 (B) 95 (C) 98 (D) 106

(86) The correct order of electronegativity for given elements is: [JEE MAIN 2023]

(A) C > P > At > Br (B) Br > P > At > C (C) P > Br > C > At (D) Br > C > At > P

7
(87) Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The first ionization enthalpy for oxygen is lower than that of nitrogen.
Reason R : The four electrons in 2p orbitals of oxygen experience more electron-electron repulsion.
In the light of the above statements, choose the correct answer from the options given below. [JEE MAIN 2022]
(A) Both A and R are correct and R is the correct (B) Both A and R are correct but R is NOT the correct
explanation of A. explanation of A.
(C) A is correct but R is not correct. (D) A is not correct but R is correct
(88) Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Metallic character decreases and non-metallic character increases on moving from left to right in a
period.
Reason (R) : It is due to increase in ionisation enthalpy and decrease in electron gain enthalpy, when one moves
from left to right in a period.
In the light of the above statements, choose the most appropriate answer from the options given below : [JEE MAIN
2021]

(A) (A) is false but (R) is true.

s
(B) (A) is true but (R) is false

as
(C) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(D) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
(89) The correct order of the ionic radii of

cl
O2− , N 3− , F − , M g 2+ , N a+ and Al3+ is [JEE MAIN 2020]
(A) Al3+ < N a+ < M g 2+ < O 2− < F − < N 3− (B) N 3− < O 2− < F − < N a+ < M g 2+ < Al3+
(C) Al3+ < M g 2+ < N a+ < F − < O 2− < N 3− (D) N 3− < F − < O 2− < M g 2+ < N a+ < Al3+

(a) C (b) O (c) F (d) Cl (e) Br [JEE MAIN 2020]

(A) (b) < (c) < (d) < (a) < (e)
on
(90) The increasing order of the atomic radii of the following elements is

(B) (a) < (b) < (c) < (d) < (e)
(C) (d) < (c) < (b) < (a) < (e) (D) (c) < (b) < (a) < (d) < (e)
iti
(91) The atomic number of the element unnilennium is [JEE MAIN 2020]
(A) 119 (B) 108 (C) 102 (D) 109
(92) The correct order of electron affinity is [JEE MAIN 2018]
Tu

(A) O > F > Cl (B) F > O > Cl (C) F > Cl > O (D) Cl > F > O
(93) Given below are two statements:
Statement (I) : Both metal and non-metal exist in p and d-block elements.
Statement (II) : Non-metals have higher ionisation enthalpy and higher electronegativity than the metals.
In the light of the above statements, choose the most appropriate answer from the option given below: [JEE MAIN 2024]
(A) Both Statement I and Statement II are false (B) Statement I is false but Statement II is true
ht

(C) Statement I is true but Statement V II is false (D) Both Statement I and Statement II are true
(94) The first ionisation potential of N a is 5.1 eV. The value of electron gain enthalpy of N a+ will be : ............... eV [JEE
ig

MAIN 2013]

(A) −2.55 (B) −5.1 (C) −10.2 (D) +2.55

(95) The correct order of metallic character is: [JEE MAIN 2023]
Br

(A) Be > Ca > K (B) Ca > K > Be (C) K > Ca > Be (D) K > Be > Ca
(96) The correct order of first ionization enthalpy values of the following elements is:
(A) O (B) N (C) Be (D) F (E) B
Choose the correct answer from the options given below : [JEE MAIN 2024]

(A) B < D < C < E < A (B) E < C < A < B < D (C) C < E < A < B < D (D) A < B < D < C < E
(97) Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason(R) :
Assertion (A) : The ionic radii of O2− and M g 2+ are same.
Reason (R) : Both O2− and M g 2+ are isoelectronic species.
In the light of the above statements, choose the correct answer from the options given below [JEE MAIN 2022]
(A) Both (A) and (R) are true and (R) is the correct explanation of (A)
(B) Both (A) and (R) are true but (R) is not the correct explanation of (A)
(C) (A) is true but (R) is false
(D) (A) is false but (R) is true

8
 (98) In comparison to boron, berylium has [JEE MAIN 2019]
(A) greater nuclear charge and greater first ionisation (B) lesser nuclear charge and lesser first ionisation
enthalpy enthalpy
(C) greater nuclear charge and lesser first ionisation (D) lesser nuclear charge and greater first ionisation
enthalpy enthalpy
(99) Match List I with List II
List-I (Elements) List-II(Properties in their respective groups)
A Cl, S I Elements with highest electronegativity
B Ge, As II Elements with largest atomic size
C Fr, Ra III Elements which show properties of both
metals and non metal
D F, O IV Elements with highest negative electron
gain enthalpy

Choose the correct answer from the options given below : [JEE MAIN 2024]

s
(A) A − II, B − III, C − IV, D − I (B) A − III, B − II, C − I, D − IV

as
(C) A − IV, B − III, C − II, D − I (D) A − II, B − I, C − IV, D − III
(100) The pair that has similar atomic radii is [JEE MAIN 2019]
(A) T i and Hf (B) M n and Re (C) Sc and N i (D) M o and W

cl
′ ′
(101) if IU P AC name of an element is U nununnium then the element belongs to nth group of periodic table. The value
of n is______ [JEE MAIN 2024]
(A) 8 (B) 15 (C) 10 (D) 11
(102) Which of these statements is not true [JEE MAIN 2014]
(A) N O+ is isoelectronic with O2
(B) B is always covalent in its compounds
on
(C) In aqueous solution, the T i+ ion is much more stable than T i(III)
iti
(D) LiAlH4 is a versatile reducing agent in organic synthesis
(103) Which of the following represents the correct order of metallic character of the given elements ? [JEE MAIN 2023]

(A) Si < Be < M g < K (B) Be < Si < M g < K (C) K < M g < Be < Si (D) Be < Si < K < M g
Tu

(104) Similarity in chemical properties of the atoms of elements in a group of the Periodic table is most closely related to
[JEE MAIN 2014]
(A) atomic numbers (B) atomic masses
(C) number of principal energy levels (D) number of valence electrons
(105) The correct order of density is [JEE MAIN 2022]
ht

(A) Be > M g > Ca > Sr (B) Sr > Ca > M g > Be

(C) Sr > Be > M g > Ca (D) Be > Sr > M g > Ca
ig

(106) Identify the correct statements about p-block elements and their compounds.
(A) Non metals have higher electronegativity than metals.
(B) Non metals have lower ionisation enthalpy than metals.
Br

(C) Compounds formed between highly reactive nonmetals and highly reactive metals are generally ionic.
(D) The non-metal oxides are generally basic in nature.
(E) The metal oxides are generally acidic or neutral in nature. [JEE MAIN 2024]

(A) (D) and (E) only (B) (A) and (C) only (C) (B) and (E) only (D) (B) and (D) only
(107) The five successive ionization enthalpies of an element are 800, 2427, 3658, 25024 and 32824 kJmol−1 . The number of
valence electrons in the element is [JEE MAIN 2020]
(A) 2 (B) 3 (C) 4 (D) 5
(108) Which of the following statements are not correct?
A. The electron gain enthalpy of F is more negative than that of Cl
B. Ionization enthalpy decreases in a group of periodic table
C. The electronegativity of an atom depends upon the atoms bonded to it.
D. Al2 O3 and N O are examples of amphoteric oxides.
Choose the most appropriate answer from the options given below: [JEE MAIN 2023]
(A) A, B, C and D (B) A, C and D Only (C) B and D Only (D) A, B and D Only

9
(109) Incorrect statements among the following is/are
(A) 2nd electron gain enthalpy is always endothermic (B) Electronegativity is the property of bonding atoms
(C) Al2 O3 and BeO are amphoteric oxide (D) None of these are incorrect
(110) Find exothermic reaction
−
(A) F(g) → F(g) + e− (B) Be(g) + e− → Be−
(g)
−
(C) O(g) + e− → O(g) −2
(D) O(g) + 2e− → O(g)
(111) The statement that is not correct for the periodic classification of elements is [IIT 1992]
(A) The properties of elements are the periodic functions of their atomic numbers
(B) Non-metallic elements are lesser in number than metallic elements
(C) The first ionisation energies along a period do not vary in a regular manner with increase in atomic number
(D) For transition elements the d-sub-shells are filled with electrons monotonically with increase in atomic
number
(112) Assertion : Electron affinity refers to an isolated atom’s attraction for an additional electron while electronegativity
is the ability of an atom of an element to attract electrons towards itself in a shared pair of electrons.

s
Reason : Electron affinity is a relative number and electronegativity is experimentally measurable. [AIIMS 2010]
(A) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

as
(B) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
(C) If the Assertion is correct but Reason is incorrect.

cl
(D) If both the Assertion and Reason are incorrect.
(113) Choose the correct order for given property
(M.P. → M eltingP oint; S → Solubility)
M.P. CaF2 > M gF2 > BeF2 ; M.P. CaO > BeO > M gO;
(A) S M gF2 < CaF2 < BeF2 on (B) S BeO < M gO < CaO

M.P. AgCl < KCl < N aCl; M.P. AgCl > KCl > N aCl;
(C) S (D) S
iti
AgCl < N aCl > KCl KI > LiI > N aI

(114) Chloride of an element A gives neutral solution in water. In the periodic table, the element A belongs to [AIIMS 1992]
(A) First group (B) Third group (C) Fifth group (D) First transition series
Tu

(115) What is the atomic number of the element with the maximum number of unpaired 4p electrons
(A) 33 (B) 26 (C) 23 (D) 15
(116) For valence shell of N a screening by
(A) 1s orbital (B) 2s orbital (C) 2p orbital (D) All
(117) The heaviest atom amongst the following is
ht

(A) U (B) Ra (C) P b (D) Hg

(118) Correct order of acidic strength
(A) HF > HCl > HBr > HI (B) H3 P O2 > H3 P O3 > H3 P O4
ig

(C) B(OH)3 > H2 CO3 > HN O3 (D) H2 O > H2 S > H2 Se > H2 T e

(119) Which one of the following elements has the highest ionisation energy [IIT 1990]
Br

(A) [N e] 3s2 3p1 (B) [N e] 3s2 3p2 (C) [N e] 3s2 3p3 (D) [Ar] 3d10 4s2 4p2
(120) The process requiring absorption of energy is
(A) N → N − (B) F → F − (C) Cl → Cl− (D) H → H −
(121) Which of the following set has highest sum of IE indica ted as compared to all other sets mentioned
(A) IE1 of He, IE2 of Li, IE2 of Ca (B) IE1 of He , IE2 of Li, IE3 of M g
(C) IE1 of Li, He and K (D) IE2 of N a, Ba and Sr
(122) The incorrect statement among the following is
(A) The first ionization potential of Al is less than the first ionization potential of M g
(B) The second ionization potential of M g is greater than the second ionization potential of N a
(C) The first ionization potential of N a is less than the first ionization potential of M g
(D) The third ionization potential of M g is greater than the third ionization potential of Al
(123) The order of the magnitude of first ionisation potentials of Be, B, N and O is
(A) N > O > Be > B (B) N > Be > O > B (C) Be > B > N > O (D) B > Be > O > N

10
(124) Arrange the following in increasing order of their atomic radius : N a, K, M g, Rb
(A) M g < K < N a < Rb (B) M g < N a < K < Rb (C) M g < N a < Rb < K (D) N a < K < Rb < M g
(125) Hydrogen by donating one electron forms H . In this property, it resembles with
+

(A) Transitional metals (B) Alkaline earth metals (C) Alkali metals (D) Halogens
(126) Which of the following may act as an oxidising and reducing agent both?
(A) K2 Cr2 O7 (B) SO2 (C) H2 S (D) N H3
(127) Which of the following isoelectronic series would lose an electron most easily ?
(A) S 2− (B) Cl− (C) Ar (D) K +
(128) The correct order of ionisation energy of C, N, O, F is :-
(A) F < N < C < O (B) C < N < O < F (C) C < O < N < F (D) F < O < N < C
(129) Which of the following arrangements shows the correct order of decreasing paramagnetism?
(A) N > Al > O > Ca (B) N > O > Al > Ca (C) O > N > Al > Ca (D) O > N > Ca > Al
(130) Which of the following statement is not correct for the element having electronic configuration 1s2 , 2s2 p6 , 3s1
(A) It is a monovalent electropositive (B) It forms basic oxide

s
(C) It is a non-metal (D) It has low electron affinity

as
(131) Astatine is a
(A) Halogen (B) Rare earth element (C) Alkaline earth metal (D) None of these
(132) When magnesium burns in air, compounds of magnesium formed are magnesium oxide and

cl
(A) M g3 N2 (B) M gCO3 (C) M g(N O3 )2 (D) M gSO4
(133) Order of first ionization potentials of elements Li, Be, B, N a is
(A) Li > Be > B > N a (B) Be > B > Li > N a (C) N a > Li > B > Be (D) Be > Li > B > N a
(134) Which one of the following species possesses maximum size
(A) N a+ (B) F −
on (C) N e
(135) Which set has the same number of unpaired electrons in their ground state
(D) O2−

(A) Cl− , F e3+ , Cr3+ (B) N a+ , M g 2+ , Al (C) N a, P, Cl (D) N, P, V

iti
− x 5 eV
(136) N a ←− N a −−−→ N a +

Predict the value of ′ X ′ is .............. eV

(A) 5 (B) 8 (C) 3 (D) Date insufficient
Tu

(137) Which of the following has minimum ionization energy

(A) Ge (B) Se (C) As (D) Br
(138) Which ionisation potential (IP ) in the following equations involves the greatest amount of energy
(A) N a → N a+ + e− (B) K + → K 2+ + e− (C) C 2+ → C 3+ + e− (D) Ca+ → Ca2+ + e−
(139) Mosley’s name is most closely associated with the discovery of
ht

(A) Positron (B) Deutrons (C) Atomic number (D) Atomic weight
(140) Which has the highest second ionisation potential [AIIMS 1991]
(A) Nitrogen (B) Carbon (C) Oxygen (D) Fluorine
ig

(141) Consider the following electronic configuration of an element (P ) :

[Xe]4f 14 5d1 6s2
Then correct statement about element ′ P ′ is
Br

(A) It belongs to 6th period and 1st group (B) It belongs to 6th period and 2nd group
(C) It belongs to 6th period and 3rd group (D) None of these
(142) A neutral atom will have the lowest ionization potential when its electronic configuration is [AIPMT 1991]
(A) 1s1 (B) 1s2 , 2s2 p6 (C) 1s2 , 2s2 p2 (D) 1s2 , 2s2 p6 , 3s1
(143) Consider the following information about element P and Q
Period number Group number
Q 2 15
P 3 2
Then formula of the compound formed by P and Q element is
(A) P Q (B) P3 Q2 (C) P2 Q3 (D) P Q2
(144) Strongest acid is
(A) Al2 O3 (B) M gO (C) N a2 O (D) CaO
(145) Highest density is of . . . . . . . . . .
(A) Ir (B) Os (C) P b (D) Hg

11
(146) Which one of the following elements shows both positive and negative oxidation states?
(A) Cesium (B) Fluorine (C) Iodine (D) Xenon
(147) The electronic configuration of an atom A is 1s2 , 2s2 p6 , 3s2 p6 d10 , 4s2 p3 . The chemistry of A is therefore likely to be
similar to that of
(A) Chlorine (B) Nitrogen (C) Oxygen (D) Boron
(148) In which of the following groups all the three members are of the alkaline earth metals family
(A) Al, Sr, T i (B) Li, N a, K (C) M g, Ba, Ca (D) Rb, Cs, F r
(149) In the periodic table, metallic character of the elements shows which one of the following trends?
(A) Decreases down the group and increases across the (B) Increases down the group and decreases across the
period period
(C) Increase across the period and also down the group (D) Decreases across the period and also down the group
(150) Which of the following element does not occur in liquid form
(A) Hg (B) Li (C) Ga (D) Br

s
as
cl
on
iti
Tu
ht
ig
Br

12
 Bright Tuition Classes

Subject : Che Classification of Elements and Paper Set : 1

Standard : 11 Periodicity in Properties Date : 30-06-2024
Total Mark : 600 Time : 0H:0M
(Answer Key)

Chemistry - Section A (MCQ)

1-D 2-D 3-D 4-D 5-A 6-B 7-A 8-D 9-A 10 - A

11 - A 12 - B 13 - C 14 - D 15 - D 16 - C 17 - A 18 - C 19 - D 20 - D

s
21 - C 22 - A 23 - D 24 - A 25 - D 26 - A 27 - C 28 - D 29 - A 30 - D
31 - B 32 - A 33 - C 34 - D 35 - C 36 - C 37 - D 38 - C 39 - B 40 - D

as
41 - C 42 - A 43 - B 44 - B 45 - C 46 - C 47 - A 48 - A 49 - A 50 - C
51 - B 52 - B 53 - D 54 - D 55 - C 56 - C 57 - C 58 - C 59 - D 60 - B

cl
61 - A 62 - D 63 - B 64 - A 65 - B 66 - C 67 - C 68 - B 69 - B 70 - B
71 - A 72 - B 73 - B 74 - A 75 - B 76 - C 77 - D 78 - A 79 - D 80 - A
81 - C 82 - B 83 - C 84 - D 85 - A 86 - D 87 - A 88 - B 89 - C 90 - D
91 - D 92 - D 93 - B 94 - B 95 - C 96 - B 97 - D 98 - D 99 - C 100 - D
101 - D 102 - A 103 - A 104 - A
111 - C 112 - C
on
105 - C 106 - B 107 - B 108 - B 109 - D
113 - A 114 - A 115 - A 116 - D 117 - A 118 - B 119 - C
110 - C
120 - A
121 - B 122 - B 123 - A 124 - B 125 - C 126 - B 127 - A 128 - C 129 - B 130 - C
iti
131 - A 132 - A 133 - B 134 - D 135 - D 136 - C 137 - A 138 - B 139 - C 140 - C
141 - C 142 - D 143 - B 144 - A 145 - B 146 - C 147 - B 148 - C 149 - B 150 - B
Tu
ht
ig
Br

13
 Bright Tuition Classes

Subject : Che Classification of Elements and Paper Set : 1

Standard : 11 Periodicity in Properties Date : 30-06-2024
Total Mark : 600 Time : 0H:0M
(Solutions)

.......................................... Chemistry - Section A (MCQ) ..........................................

(1) Arrange the following elements in increasing order of electronegativity:

N, O, F, C, Si
Choose the correct answer from the options given below: [NEET 2024]

(A) Si < C < O < N < F (B) O < F < N < C < Si (C) F < O < N < C < Si (D) Si < C < N < O < F
Solution:(Correct Answer:D)
Electronegativity increases across the period on moving left to right. It decreases on moving down the group.
The correct option is Si < C < N < O < F

(2) Which of the following orders of ionic radii is correctly represented ? [NEET 2014]

(A) H − > H + > H (B) N a+ > F − > O 2− (C) F − > O 2− > N a+ (D) None of the above
Solution:(Correct Answer:D)
Cations lose electrons and are smaller in size than the parent atom, whereas anions add electrons and are larger
in size than the parent atom. Hence, the order is H− > H > H+

s
For isoelectronic species, the ionic radii decreases with increase in atomic number
i.e. nuclear charge. Hence, the correct orders are O2− > F− > Na+ and N3− > Mg2+ > Al
3+
as
(3) In which of the following options the order of arrangement does not agree with the variation of property
indicated against it ? [NEET 2016]
(A) I < Br < Cl < F (increasing electron gain enthalpy) (B) Li < N a < K < Rb (increasing metallic radius)
cl

(C) B < C < N < O (increasing first ionisation enthalpy)(D) Both (a) and (c)
Solution:(Correct Answer:D)
d

The correct order of increasing negative electron gain enthalpy is: I < Br < F < C and the correct order of
increasing first ionisation enthalpy is B < C < O < N
Ve

(4) Which one of the following arrangements represents the correct order of least negative to most negative electron
gain enthalpy for C, Ca, Al, F and O ? [NEET 2013]
(A) Al < Ca < O < C < F (B) Al < O < C < Ca < F (C) C < F < O < Al < Ca (D) Ca < Al < C < O < F
Solution:(Correct Answer:D)
Variation of electron gain enthalpy in periodic table-
1. Electron gain enthalpy decreases down the group.
2. generally, electron gains enthalpy increases (more negative) along the period.
Electron gain enthalpy increases along the period as the attraction between incoming electron and the nucleus
increases.
Also, it decreases down the group due to increased atomic size.
∴ Increasing order of electron gain enthalpy:
Ca < Al < C < O < F

(5) The element Z = 114 has been discovered recently. It will belong to which of the following family/group and
electronic configuration? [NEET 2017]
(A) Carbon family, [Rn] 5f 14 6d10 7s2 7p2 (B) Oxygen family, [Rn] 5f 14 6d10 7s2 7p4
(C) Nitrogen family, [Rn] 5f 14 6d10 7s2 7p6 (D) Halogen family, [Rn] 5f 14 6d10 7s2 7p5
Solution:(Correct Answer:A)
Z = 114[Rn]86 7s2 5f14 6d10 7p2
14th gp. (carbon family)

(6) For the second period elements the correct increasing order of first ionisation enthalpy is [NEET 2019]
(A) Li < Be < B < C < N < O < F < Ne (B) L < B < Be < C < O < N < F < Ne
(C) Li < B < Be < C < N < O < F < Ne (D) Li < Be < B < C < O < N < F < Ne

14
 Solution:(Correct Answer:B)
For
[ 1 same shell ]
s < p1 < s 2 < p2 < p4 < p3 < p5 < p6
B < Be < C < O < N < F < N e

(7) Identify the incorrect match :

Name IU P AC Official Name
(a) Unnilunium (i) Mendelevium
(b) Unniltrium (ii) Lawrencium
(c) Unnilhexlum (iii) Seaborglum
(d) Unununnium (iv) Darmstadtium [NEET 2020]
(A) (d), (iv) (B) (a), (i) (C) (b), (ii) (D) (c), (iii)
Solution:(Correct Answer:A)
Unununium (Z = 111) it is Rontgentum (Rg) not darmstadtium.

(8) The IU P AC name of an element with atomic number 119 is ......... [NEET 2022]

(A) unnilennium (B) unununnium (C) ununoctium (D) ununennium

Solution:(Correct Answer:D)
IU P AC nomenclature
119 → Ununennium → Uue

(9) Arrange the following elements in increasing order of first ionization enthalpy:
Li, Be, B, C, N
Choose the correct answer from the options given below: [NEET 2024]

(A) Li < B < Be < C < N (B) Li < Be < C < B < N (C) Li < Be < N < B < C (D) Li < Be < B < C < N
Solution:(Correct Answer:A)

s
as
Increasing order of first ionization enthalpy is Li < B < Be < C < N
Element First
( ionization )enthalpy
∆i H/kJ mol−1
Li
cl
520
Be 899
B 801
d

C 1086
Ve

N 1402

(10) The species Ar, K + and Ca2+ contain the same number of electrons. In which order do their radii increase ? [NEET
2015]

(A) Ca2+ < K + < Ar (B) K + < Ar < Ca2+ (C) Ar < K + < Ca2+ (D) Ca2+ < Ar < K +
Solution:(Correct Answer:A)
Atomic radius and lonic radius ∝ 1
Zeffective

o
(11) The ionic radii (in A) of N 3− , O 2− and F − are respectively : [JEE MAIN 2015]

(A) 1.71, 1.40 and 1.36 (B) 1.71, 1.36 and 1.40 (C) 1.36, 1.40 and 1.71 (D) 1.36, 1.71 and 1.40
Solution:(Correct Answer:A)
The ionic radii (in Ȧ ) of N 3− , O2− and F − are respectively 1.71,1.40 and 1.36.
N 3− , O 2− and F − contains ten electrons each. Hence, they are isoelectronic species.
For isoelectronic species, the nuclear charge increases on moving from left to right in a period.
This decreases the ionic radii as the valence electrons are more strongly attracted by the nucleus.

(12) Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation
correctly is: (Given v = frequency of X-ray emitted; Z = atomic number) [JEE MAIN 2023]
(A) (B) (C) (D)

15
 Solution:(Correct Answer:B)
√
vαZ

(13) Given below are two statements:

Statement- I: Along the period, the chemical reactivity of the element gradually increases from group 1 to group
18.
Statement - II: The nature of oxides formed by group 1 element is basic while that of group 17 elements is
acidic.In the the light above statements, choose the most appropriate from the questions given below: [JEE MAIN 2024]
(A) Both statement I and Statement II are true. (B) Statement I is true but Statement II is False.
(C) Statement I is false but Statement II is true. (D) Both Statement I and Statement II is false.
Solution:(Correct Answer:C)
Chemical reactivity of elements decreases along the period therefore statement −I is false.
Group − 1 elements from basic nature oxides while group - 17 elements form acidic oxides therefore statement −II
is true.
3+
(14) The ionic radii of K+ , Na+ , Al and Mg2+ are in the order: [JEE MAIN 2021]
3+ 3+
(A) Al < Mg2+ < K+ < Na+ (B) K+ < Al < Mg2+ < Na+
3+ 3+
(C) Na+ < K+ < Mg2+ < Al (D) Al < Mg2+ < Na+ < K+
Solution:(Correct Answer:D)
3+
Al , Mg2+ and Na+ are isoelectronic ionic species. For monoatomic ionic isoelectronic species as positive charge
increases ionic size decrease.
The order of size of Na+ & K+ is Na+ < K+ ,
3+
∴ order of ionic radii is : Al < Mg2+ < Na+ < K+

(15) The ionic radii of O2 − F − , N a+ and M g 2+ are in the order : [JEE MAIN 2020]
(A) F − > O 2− > N a+ > M g 2+

s
(B) M g 2+ > N a+ > F − > O 2−
as
(C) O2− > F − > M g 2+ > N a+ (D) O2− > F − > N a+ > M g 2+
Solution:(Correct Answer:D)
O−2 F− N a+ M g 2+
cl
Z 8 9 11 12
−
e 10 10 10 10
d

z
e
0.8 0.9 1.1 1.2
as ratio increases size decreases.
z
e
Thus correct ionic radiit order is O−2 > F − > N a+ > M g 2+
Ve

Therefore correct option is (4)

(16) Which of the following represents the correct order of increasing first ionization enthalpy for Ca, Ba, S, Se and Ar
? [JEE MAIN 2013]
(A) Ca < S < Ba < Se < Ar (B) S < Se < Ca < Ba < Ar
(C) Ba < Ca < Se < S < Ar (D) Ca < Ba < S < Se < Ar
Solution:(Correct Answer:C)
B
enthalpy increases along the period but decreases down the group.

The IE of an element increases as one moves across a period in the periodic table because the
electrons are held tighter by the higher effective nuclear charge.
The ionization energy of the elements decreases as one moves down the group because the electrons are held in
lower-energy orbitals, away from the nucleus and therefore, are less tightly bound.
Ar has higher IE because it is a noble gas and Ba has the lowest IE as it is in 6 periods and more
metallic.
Hence, the correct option is C

(17) Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in +1 and +3 oxidation states. This
is due to [JEE MAIN 2019]
(A) inert pair effect (B) diagonal relationship (C) lattice effect (D) lanthanoid contraction
Solution:(Correct Answer:A)
The outermost electron configuration of T l is 6s2 6p1 . The 6s electrons are strongly attracted towards the nucleus
due to its more penetrating power and deshielding of d and f − electrons. Hence 6s electrons do not participate in
bonding

16
(18) Among the following basic oxide is ..... [JEE MAIN 2022]

(A) SO3 (B) SiO2 (C) CaO (D) Al2 O3

Solution:(Correct Answer:C)
SO3 , SiO2 = Acidic
CaO = Basic
Al2 O3 = Amphoteric

(19) The statement(s) that are correct about the species O2− , F− , Na+ and Mg2+ .
(A) All are isoelectronic
(B) All have the same nuclear charge
(C) O2− has the largest ionic radii
(D) Mg2+ has the smallest ionic radii
Choose the most appropriate answer from the options given below : [JEE MAIN 2024]

(A) (B), (C) and (D) only (B) (A), (B), (C) and (D) (C) (C) and (D) only (D) (A), (C) and (D) only

Solution:(Correct Answer:D)
O−2 F− Na+ Mg+2
(No. of e− ) 10 10 10 10
(Ionic radius) O−2 > F− > Na+ > Mg+2
Zeff O−2 < F− < Na+ < Mg−2

(20) The IU P AC nomenclature of an element with electronic configuration [Rn]5f 14 6d1 7s2 is. [JEE MAIN 2022]

(A) U nnilbium (B) U nnilunium (C) U nnilquadium (D) U nniltrium

Solution:(Correct Answer:D)
Atomic Number 103

s
as
(21) For elements B, C, N, Li, Be, O and F the correct order of first ionization enthalpy is [JEE MAIN 2023]
(A) Li < Be < B < C < N < O < F (B) B > Li > Be > C > N > O > F
(C) Li < B < Be < C < O < N < F (D) Li < Be < B < C < O < N < F
cl
Solution:(Correct Answer:C)
First I.E.
d

F > N > O > C > Be > B > Li

Li − 520 kJ/mol
Be − 899 kJ/mol
Ve

B − 801 kJ/mol
C − 1086 kJ/mol
N − 1402 kJ/mol
O − 1314 kJ/mol
F − 1681 kJ/mol

(22) Which one of the following has largest ionic radius? [JEE MAIN 2014]

(A) O22− (B) Li+ (C) B 3+ (D) F −

Solution:(Correct Answer:A)
On moving along a period ionic radii decreases due to increase in effective nuclear charge

(23) Given below are two statements :

Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on
the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement (II) : pπ − pπ bond formation is more prevalent in second period elements over other periods.
In the light of the above statements, choose the most appropriate answer from the options given below : [JEE MAIN
2024]
(A) Both Statement I and Statement II are incorrect (B) Statement I is correct but Statement II is incorrect
(C) Both Statement I and Statement II are correct (D) Statement I is incorrect but Statement II is correct
Solution:(Correct Answer:D)
Oxidation state of an element in a particular compound is defined by the charge acquired by its atom on the basis
of electronegativity consideration from other atoms in molecule.

(24) The first ionization energy (in kJ/mol ) of N a, Mg, Al and Si respectively, are [JEE MAIN 2020]
(A) 496, 737, 577, 786 (B) 786, 737, 577, 496 (C) 496, 577, 737, 786 (D) 496, 577, 786, 737

17
 Solution:(Correct Answer:A)
Elecronic configuration of Na = [Ne]3s1
Mg = [Ne]3s2
Al = [Ne]3s2 3p1
So order of first ionisation energy is
Na(496) < Mg(737) > Al(577) < Si (786)
Na < Al < Mg < Si (IE1 order )

(25) In case of isoelectronic species the size of F− , Ne and Na+ is affected by: [JEE MAIN 2024]
(A) Principal quantum number (n) (B) None of the factors because their size is the same
(C) Electron-electron interaction in the outer orbitals (D) Nuclear charge (z)

Solution:(Correct Answer:D)
In F− , Ne, Na+ all have 1 s2 , 2 s2 , 2p0 configuration. They have different size due to the difference in nuclear charge.

(26) The element with which of the following outer electron configuration may exhibit the largest number of oxidation
states in its compounds [JEE MAIN 2013]
(A) 3d5 4s2 (B) 3d8 4s2 (C) 3d7 4s2 (D) 3d6 4s2

Solution:(Correct Answer:A)
The element with outer electron configuration 3d5 4s2 is M n which exhibits oxidation states from +2 to +7

(27) The electronic configuration with the highest ionization enthalpy is [JEE MAIN 2017]
(A) [N e] 3s2 3p1 (B) [N e] 3s2 3p2 (C) [N e] 3s2 3p3 (D) [Ar] 3d10 4s2 4p3

Solution:(Correct Answer:C)
The smaller the atomic size, larger is the value of IP . Further the atoms having half filled or fully filled orbitals

s
are comparatively more stable, hence more energy required to remove the electron from such atoms.
as
(28) In general, the property (magnitudes only) that shows an opposite trend in comparison to other properties across
a period is [JEE MAIN 2020]
(A) Electronegativity (B) Electron gain enthalpy (C) Ionization enthalpy (D) Atomic radius
cl
Solution:(Correct Answer:D)
In general across a period atomic radius decreases while ionisation enthalpy, electron gain enthalpy and
electronegativity increases because effective nuclear charge (Zeff ) increases.
d

(29) Element ′ E ′ belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of
Ve

the element, which is just above ′ E ′ in the group is ..... [JEE MAIN 2022]
(A) 3s2 · 3p4 (B) 3d10 · 4s2 , 4p4 (C) 4d10 · 5s2 , 5p4 (D) 2s2 , p4

Solution:(Correct Answer:A)
E ⇒ [Ar]3d10 4s2 4p4
Element above E ⇒ [N e]3s2 3p4

(30) The electron affinity value are negative for :

A. Be → Be−
B. N → N−
C. O → O2−
D. Na → Na−
−
E. Al → Al
Choose the most appropriate answer from the options given below : [JEE MAIN 2024]
(A) D and E only (B) A, B, D and E only (C) A and D only (D) A, B and C only

Solution:(Correct Answer:D)
(A) Be + e− → Be− , E.A =-ive
(B) N + e− → N− E.A = − ive
(C) O + e− → O−
O− + e− → O−2 E.A = − ive
(D) Na + e− → Na− E.A = + ive
(E) Aℓ + e− → Aℓ− E.A = + ive
Ans. A, B and C only

18
(31) Given below are the oxides:
N a2 O, As2 O3 , N2 O, N O and Cl2 O7
Number of amphoteric oxides is ..... . [JEE MAIN 2022]

(A) 0 (B) 1 (C) 2 (D) 3

Solution:(Correct Answer:B)
N a2 O = Basic
N2 O = Neutral
Cl2 O7 = Acidic
As2 O3 = Amphoteric
N O = Neutral

(32) Which of the following arrangements represents the increasing order ( smallest to largest) of ionic radii of the
given species O2− , S 2− , N 3− , P 3− ? [JEE MAIN 2014]
(A) O2− < N 3− < S 2− < P 3− (B) O2− < P 3− < N 3− < S 2−
(C) N 3 < O2− < P 3− < S 2− (D) N 3− < S 2− < O2− < P 3−

Solution:(Correct Answer:A)
For isoelectronic species ionic radii decreases as the charge on ion decreases. Further on moving down in a group
ionic radii increases. Hence the correct order is
O2− < N 3− < S 2− < P 3−

(33) Which of the following series correctly represents relations between the elements from X to Y ? X → Y [JEE MAIN
2014]
(A) 3 Li → 19 K Ionization enthalpy increases (B) 9 F → 35 Br Electron gain enthalpy (negative sign)
increases
(C) 6 C → Atomic radii increases (D) → Noble character increases

s
32 Ge 18 Ar 54 Xe

Solution:(Correct Answer:C)
as
On moving down a group atomic radii increases

(34) The correct order of the first ionization enthalpy is [JEE MAIN 2024]
cl
(A) Al > Ga > Tl (B) Ga > Al > B (C) B > Al > Ga (D) Tl > Ga > Al

Solution:(Correct Answer:D)
(i) due to lanthanide contraction Tℓ has more I.E. as compared to Ga and Aℓ
d

(ii) due to scandide contraction Ga has more I.E. as compared to Aℓ

Ve

(35) In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical ?
(A) Rb and Cs
(B) N a and K
(C) Ar and Kr
(D) I and At
Choose the correct answer from the options given below. [JEE MAIN 2022]
(A) (A) and (B) only (B) (B) and (C) only (C) (A) and (C) only (D) (C) and (D) only

Solution:(Correct Answer:C)
Rb and Cs have nearly same electron gain enthalpy electron gain enthalpy = −46 kj/ml
Ar and Kr have same ∆Heq . Value is +96 kj/ml

(36) Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R : Assertion
A : The first ionisation enthalpy decreases across a period.
Reason R : The increasing nuclear charge outweighs the shielding across the period.
In the light of the above statements, choose the most appropriate from the options given below: [JEE MAIN 2024]
(A) Both A and R are true and R is the correct explanation of A
(B) A is true but R is false
(C) A is false but R is true
(D) Both A and R are true but R is N OT the correct explanation of A

Solution:(Correct Answer:C)
First ionisation energy increases along the period. Along the period Z increases which outweighs the shielding
effect

19
(37) The first ionization enthalpies of Be, B, N and O follow the order.... [JEE MAIN 2022]

(A) O < N < B < Be (B) Be < B < N < O (C) B < Be < N < O (D) B < Be < O < N

Solution:(Correct Answer:D)
1st I.E. N3 > O4 > Be2 > B1
(2p ) (2p ) (2s ) (2p )

(38) The element having the highest first ionization enthalpy is [JEE MAIN 2024]
(A) Si (B) Al (C) N (D) C

Solution:(Correct Answer:C)
Al < Si < C < N; IE1 order.

(39) The correct option with respect to the Pauling electronegativity values of the elements is [JEE MAIN 2019]
(A) T e > Xe (B) Ga > Ge (C) Si > Al (D) P > S

Solution:(Correct Answer:B)
Electronegativity increases from left to right in a period and decreases down the group

(40) The size of the iso-electronic species Cl− , Ar and Ca2+ is affected by [JEE MAIN 2019]
(A) Principal quantum number of valence shell (B) Azimuthal quantum number of valence shell
(C) electron -electron interaction in the outer orbitals (D) nuclear charge

Solution:(Correct Answer:D)
For isoelectronic species the size is compared by nuclear charge.
Size ∝ Z (Nuclear
1
Charge)

s
(41) The ionic radii of F− and O2− respectively are 1.33 Ao and 1.4 Ao , while the covalent radius of N is 0.74 Ao
The correct statement for the ionic radius of N3− from the following is : [JEE MAIN 2021]
as
(A) It is bigger than F− and N, but smaller than of O2− (B) It is smaller than O2− and F− , but bigger than of N
(C) It is bigger than O2− and F− (D) It is smaller than F− and N

Solution:(Correct Answer:C)
cl
F− , O2− and N3− all are isoelectronic species inwhich N3− have least number of protons due to which it’s size
increases as least nuclear attractionis experienced by the outer shell electrons. Size order N3− > O2− > F−
d

(42) Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : The first ionization enthalpy of 3d series elements is more than that of group 2 metals
Ve

Reason (R) : In 3d series of elements successive filling of d-orbitals takes place.

In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2023]
(A) Both (A) and (R) are true and (R) is the correct explanation of (A)
(B) Both (A) and (R) are true but (R) is not the correct explanation of (A)
(C) (A) is false but (R) is true
(D) (A) is true but (R) is false

Solution:(Correct Answer:A)
From Sc to Mn ionization energy is less than that of M g.

20
(43) Match List−I with List−II.

List−I List−II
(Oxide) (Nature)

(A) Cl2 O7 (I) Amphoteric

(B) N a2 O (II) Basic
(C) Al2 O3 (III) Neutral
(D) N2 O (IV ) Acidic
Choose the correct answer from the options given below [JEE MAIN 2022]
(A) (A) − (IV ), (B) − (III), (C) − (I), (D) − (II) (B) (A) − (IV ), (B) − (II), (C) − (I), (D) − (III)
(C) (A) − (II), (B) − (IV ), (C) − (III), (D) − (I) (D) (A) − (I), (B) − (II), (C) − (III), (D) − (IV )

Solution:(Correct Answer:B)
Cl2 O7 Acidic
N a2 O Basic
Al2 O3 Amphoteric
N2 O Neutral

(44) The correct sequence of electron gain enthalpy of the elements listed below is
A. Ar B. Br C.F D. S
Choose the most appropriate from the options given below: [JEE MAIN 2024]
(A) C > B > D > A (B) A > D > B > C (C) A > D > C > B (D) D > C > B > A

Solution:(Correct Answer:B)

s
Element ∆eg H(kJ/mol)
F − 333 S − 200 Br − 325 Ar + 96
as
(45) In the long form of the periodic table, the valence shell electronic configuration of 5s2 5p4 corresponds to the
element present in [JEE MAIN 2015]
(A) Group 16 and period 6 (B) Group 17 and period 6 (C) Group 16 and period 5 (D) Group 17 and period 5
cl

Solution:(Correct Answer:C)
Tellurium (T e) has 5s2 5p4 valence shell configuration. It belongs to group 16 and present in period 5 of the
d

periodic table.

(46) The most polar compound among the following is [JEE MAIN 2018]
Ve

(A) (C) (D)

(B)

Solution:(Correct Answer:C)
Among the substituents attached to the given compounds, fluorine has maximum electronegativity. So it will push
electron pair towards it self. In option (b), the two F groups are attached opposite to each other thus net dipole
moment will cancel each other and reduce its polarity. In option (d), the F groups are attached in slightly opposite
direction thus this also decreases its polarity. But in option (c), the compound has the two F groups along same
direction. Thus net dipole moment will increase in this direction thus it will have maximum polarity. Thus the
compound in option (c) has maximum polarity

(47) The third ionization enthalpy is minimum for [JEE MAIN 2020]
(A) F e (B) N i (C) Co (D) M n

Solution:(Correct Answer:A)
Electronic configuration of
25 Mn 26 Fe 27 Co 28 N i
M = [Ar]3d3 4s2 [Ar]3d6 4s2 [Ar]3d7 4s2 [Ar]3d2 4s2
M2+ = [Ar]3d3 4s0 [Ar]3d6 4s0 [Ar]3d7 4s0 [Ar]3d2 4s6
So third ionisation energy is minimum for F e

21
(48) These are physical properties of an element
(A) Sublimation enthalpy
(B) Ionisation enthalpy
(C) Hydration enthalpy
(D) Electron gain enthalpy
The total number of above properties that affect the reduction potential is ...... . [JEE MAIN 2021]

(A) 3 (B) 4 (C) 5 (D) 6

Solution:(Correct Answer:A)
Sublimation enthalpy, Ionisation enthalpy and hydration enthalpy affect the reduction potential.

(49) Aqueous solution of which salt will not contain ions with the electronic configuration 1s2 2s2 2p6 3s2 3p6 ? [JEE MAIN
2016]

(A) N aF (B) KBr (C) N aCl (D) CaI2

Solution:(Correct Answer:A)
N aF is composed of N a+ and F −
N a+ → [He] 2s2 2p6
F − → [He] 2s2 2p6
Hence do not match with the configuration given in the question.

(50) Electron gain enthalpy with negative sign of fluorine is less than that of chlorine due to [JEE MAIN 2013]
(A) High ionization enthalpy of fluorine (B) Smaller size of chlorine atom
(C) Smaller size of fluorine atom (D) Bigger size of 2p orbital of fluorine

Solution:(Correct Answer:C)
The electron gain enthalpy order for halogens is
Cl > F > Br > I

s
Due to small size of fluorine the extra electron to be added feels more electron-electron repulsion. Therefore
as
fluorine has less value for electron affinity than chlorine

(51) The CORRECT order of first ionisation enthalpy is: [JEE MAIN 2021]

(A) Mg < Al < S < P (B) Al < Mg < S < P (C) Mg < Al < P < S (D) Mg < S < Al < P
cl

Solution:(Correct Answer:B)
Mg AIPS → I.E. order → Al < Mg < S < P
d

Mg Al P S
Valence [Ne ] : 3 s2 3 s2 3p1 3 s2 3p3 3 s2 3p4
Ve

↑ ↑
Full Filled Stable Half Filled Stable

(52) Outermost electronic configurations of four elements A, B, C, D are given below.

3s2 ; 3s2 3p1 ; 3s2 3p3 ; 3s2 3p4
The correct order of first ionization enthalpy for them is. [JEE MAIN 2022]
(A) (A) < (B) < (C) < (D) (B) (B) < (A) < (D) < (C) (C) (B) < (D) < (A) < (C) (D) (B) < (A) < (C) < (D)

Solution:(Correct Answer:B)
3s2 → M g
3s2 3p1 → Al
3s2 3p3 → P
3s2 3p4 → S
C>D>A>B

(53) Which of the following presents the correct order of second ionization enthalpies of C, N, O and F ? [AIEEE 2012 , JEE
MAIN 2013]

(A) F > O > N > C (B) O > N > F > C (C) C > N > O > F (D) O > F > N > C

Solution:(Correct Answer:D)
In a period the value of ionisation potential increases from left to right with breaks where the atoms have some
what stable configuration. After removing an e− oxygen will acquire stable configuration. Hence O+ has highest
second ionisation enthalpy than F + and N + .
correct order is O > F > N > C

(54) The acidic, basic and amphoteric oxides, respectively, are [JEE MAIN 2020]
(A) MgO, Cl2 O, Al2 O3 (B) Cl2 O, CaO, P4 O10 (C) Na2 O, SO3 , Al2 O3 (D) N2 O3 , Li2 O, Al2 O3

22
 Solution:(Correct Answer:D)
1. M gO Basic
Cl2 O Acidic
Al2 O3 amphoteric
2. Cl2 O Acidic
CaO Basic
P4 O10 Acidic
3. Na2 O Basic
SO3 Acidic
Al2 O3 amphoteric
4. N2 O3 Acidic
Li2 O Basic
Al2 O3 amphoteric

(55) Consider the following ionization enthalpies of two elements ′ A′ and ′ B ′ .

Element Ionization enthalpy (kJ/mol)
st nd
1 2 3rd
A 899 1757 14847
B 737 1450 7731
Which of the following statements is correct ? [JEE MAIN 2017]

(A) Both ′ A′ and ′ B ′ belong to group −1 where ′ B ′ comes below ′ A′ .

(B) Both ′ A′ and ′ B ′ belong to group −1 where ′ A′ comes below ′ B ′ .
(C) Both ′ A′ and ′ B ′ belong to group −2 where ′ B ′ comes below ′ A′ .
(D) Both ′ A′ and ′ B ′ belong to group −2 where ′ A′ comes below ′ B ′
Solution:(Correct Answer:C)

s
Generally, the ionization enthalpies or energy increases from left to right in a period and decreases from top to
as
bottom in a group. Several factor such as atomic radius, nuclear charge, shielding effect are responsible for
change of ionization enthalpies Here, 1st ionization enthalpy of A and B is greater than group I (Li 520 kJ mol−1 to
Cs 374 kJ mol−1 ), which means element A and B belong to group −2 and all three given ionization enthalpy values
are less for element B means B will come below A.
cl

(56) In general, the properties that decrease and increase down a group in the periodic table respectively are [JEE MAIN
2019]
d

(A) atomic radius and electronegativity (B) electron gain enthalpy and electronegativity
(C) electronegativity and atomic radius (D) electronegativity and electron gain enthalpy
Ve

Solution:(Correct Answer:C)
On moving down a group, electronegativity decreases and atomic radius increases for representative elements.

(57) The first ionization enthalpy of N a, M g and Si, respectively, are: 496, 737 and 786 kJ mol−1 . The first ionization
enthalpy (kJ mol−1 ) of Al is [JEE MAIN 2022]
(A) 487 (B) 768 (C) 577 (D) 856
Solution:(Correct Answer:C)
I.E : N a < Al < M g < Si
∴ 496 < IE(Al) < 737
Option (C), matches the condition.
i.e IE(Al) = 577 kJmol−1

(58) It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power ’ n ’ i.e.
v n of X-rays emitted is plotted against atomic number ’ Z ’, following graph is obtained. The value of ’ n ’ is [JEE MAIN
2023]

(A) 1 (B) 2 (C) 0.5 (D) 3

23
 Solution:(Correct Answer:C)
√
According to Henry Moseley v αz − b
So n = 21

(59) The incorrect statement is [JEE MAIN 2022]

(A) The first ionization enthalpy of K is less than that of N a and Li
(B) Xe does not have the lowest first ionization enthalpy in its group
(C) The first ionization enthalpy of element with atomic number 37 is lower than that of the element with atomic
number 38 .
(D) The first ionization enthalpy of Ga is higher than that of the d−block element with atomic number 30.
Solution:(Correct Answer:D)
Ionization enthalpy order :
Li > N a > K
He > N e > Ar > Kr > Xe > Rn
Sr > Rb
Zn > Ga

(60) The following statements concern elements in the periodic table. Which of the following is true ? [JEE MAIN 2016]

(A) For Group 15 elements, the stability of +5 oxidation state increases down the group
(B) Elements of Group 16 have lower ionization enthalpy values compared to those of Group 15 in the
corresponding periods
(C) The Group 13 elements are all metals
(D) All the elements in Group 17 are gases

s
Solution:(Correct Answer:B)
Due to extra stable half-filled p− orbital electronic configurations of Group 15 elements, larger amount of energy
as
is required to remove electrons compared to Group 16 elements

(61) B has a smaller first ionization enthalpy than Be. Consider the following statements :
(I) It is easier to remove 2p electron than 2s electron
cl
(II) 2p electron of B is more shielded from the nucleus by the inner core of electrons than the 2s electrons of Be.
(III) 2s electron has more penetration power than 2p electron.
(IV ) atomic radius of B is more than Be
d

(Atomic number B = 5, Be = 4 )
The correct statements are [JEE MAIN 2020]
(A) (I), (II) and (III) (B) (II), (III) and (IV ) (C) (I), (III) and (IV ) (D) (I), (II) and (IV )
Ve

Solution:(Correct Answer:A)
Be ⇒ 1s2 2s2
B ⇒ 1s2 2s2 2p1
B has a smaller size than Be
it is easier to remove 2p electron than 2s
electron due to less pentration effect of 2p than 2s
2p electron of Boron is more shielded from the nucleus by the inner core of electron than the 2s electron of Be
B has a smaller size than Be

(62) Given below are two statements:

Statement I: Fluorine has most negative electron gain enthalpy in its group.
Statement II: Oxygen has least negative electron gain enthalpy in its group.
In the light of the above statements, choose the most appropriate from the options given below. [JEE MAIN 2024]
(A) Both Statement I and Statement II are true (B) Statement I is true but Statement II is false
(C) Both Statement I and Statement II are false (D) Statement I is false but Statement II is true
Solution:(Correct Answer:D)
Statement−1 is false because chlorine has most negative electron gain enthalpy in its group

(63) The metal that has very low melting point and its periodic position is closer to a metalloid is. [JEE MAIN 2022]

(A) Al (B) Ga (C) Se (D) In

Solution:(Correct Answer:B)
Al → 933 K
Ga → 303 K
In → 430 K
Se → 490 K

24
(64) Given below are two statements:
Statement I : The correct order of first ionization enthalpy values of Li, Na, F and Cl is Na < Li < Cl < F.
Statement II : The correct order of negative electron gain enthalpy values of Li, Na, F and Cl is Na < Li < F < Cl
In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2024]
(A) Both Statement I and Statement II are true (B) Both Statement I and Statement II are false
(C) Statement I is false but Statement II is true (D) Statement I is true but Statement II is false
Solution:(Correct Answer:A)
null

(65) The IU P AC symbols for the element with atomic number 119 would be: [JEE MAIN 2019]

(A) U un (B) U ue (C) U uh (D) U ub

Solution:(Correct Answer:B)
The IU P AC name of element having atomic number 119 is “Ununennium”. So its symbol is uue

(66) The 71st electron of an element X with an atomic number of 71 enters into the orbital: [JEE MAIN 2019]

(A) 6p (B) 4f (C) 5d (D) 6s

Solution:(Correct Answer:C)
The electron configuration is [Xe]4f 14 5d1 6s2

s
as
(67) For N a+ , M g 2+ , F − and O2− ; the correct order of increasing Ionic radii is [JEE MAIN 2018]
(A) O2− < F − < N a+ < M g 2+ (B) N a+ < M g 2+ < F − < O 2−
(C) M g 2+ < N a+ < F − < O 2− (D) M g 2+ < O 2− < N a+ < F −
cl
Solution:(Correct Answer:C)
All species are isoelectronic (10e− ). isoelectronic series, when negative charge increases the radius of ion increases
d

∴ M g 2+ < N a+ < F − < O 2−

(68) The difference between electron gain enthalpies will be maximum between: [JEE MAIN 2023]
Ve

(A) N e and F (B) N e and Cl (C) Ar and Cl (D) Ar and F

Solution:(Correct Answer:B)
Cl has the most negative ∆Heg among all the elements and N e has the most positive ∆Heg .

(69) Which is the correct order of second ionization potential of C, N, O and F in the following ? [JEE MAIN 2013]

(A) O > N > F > C (B) O > F > N > C (C) F > O > N > C (D) C > N > O > F
Solution:(Correct Answer:B)
The second ionization potential means removal of electron from cation
C + = 1s2 2s2 2p1 , N + = 1s2 2s2 2p2
O+ = 1s2 2s2 2p3 , F + = 1s2 2s2 2p4
Therefore O > F > N > C

(70) Match List−I with List−II :

List−I List−II
(Metal Ion) (Group in Qualitative analysis)

(a) M n2+ (i) Group −III

(b) As3+ (ii) Group −IIA
(c) Cu 2+
(iii) Group −IV
(d) Al 3+
(iv) Group −IIB
Choose the most appropriate answer from the options given below : [JEE MAIN 2021]
(A) (a) − (i), (b) − (ii), (c) − (iii), (d) − (iv) (B) (a) − (iii), (b) − (iv), (c) − (ii), (d) − (i)
(C) (a) − (i), (b) − (iv), (c) − (ii), (d) − (iii) (D) (a) − (iv), (b) − (ii), (c) − (iii), (d) − (i)

25
 Solution:(Correct Answer:B)
Mn2+ → III group
As3+ → IIB group
Cu2+ → IIA group
3+
Al → IV group

(71) The correct order of the atomic radii of C, Cs, Al and S is [JEE MAIN 2019]
(A) C < S < Al < Cs (B) S < C < Cs < Al (C) S < C < Al, Cs (D) C < S < Cs < Al
Solution:(Correct Answer:A)
On moving down size increases.

(72) Which one of the following statements for D.I. Mendeleeff, is incorrect? [JEE MAIN 2021]

(A) At the time, he proposed Periodic Table of elements structure of atom was known.
(B) Element with atomic number 101 is named after him.
(C) He invented accurate barometer.
(D) He authored the textbook − Principles of Chemistry.

Solution:(Correct Answer:B)
At the time, he proposed the periodic table but structure of atom was unknown.

(73) The element with Z = 120 (not yet discovered) will be an/a [JEE MAIN 2019]

(A) Inner transition metal (B) Alkaline earth metal (C) Alkali metal (D) Transition metal
Solution:(Correct Answer:B)
[Og118 ] 8s2 is configuration for Z = 120, where Og is oganesson
As per the configuration it is in II nd group.

s
(74) The correct decreasing order for metallic character is [JEE MAIN 2022]
as
(A) N a > M g > Be > Si > P (B) P > Si > Be > M g > N a
(C) Si > P > Be > N a > M g (D) Be > N a > M g > Si > P
Solution:(Correct Answer:A)
cl
Across a period metallic character decreases

(75) Consider the following elements.

d

Which of the following is/are true about A′ , B′ , C′ and D′ ?

A. Order of atomic radii: B′ < A′ < D′ < C′
Ve

B. Order of metallic character: B′ < A′ < D′ < C′

C. Size of the element : D′ < C′ < B′ < A′
D. Order of ionic radii : B′+ < A′+ < D′+ < C′+
Choose the correct answer from the options given below : [JEE MAIN 2024]

(A) A only (B) A, B and D only (C) A and B only (D) B, C and D only
Solution:(Correct Answer:B)
In general along the period from left to right, size decreases and metallic character decrease.In general down the
group, size increases and metallic character increases.
B′ < A′ ( size ) C′ > A′ ( size )
D′ < C′ ( size ) D′ > B′ ( size )
B′ < A′ ( metallic character )
D′ < C′ ( metallic character )
B′+ < A′+ ( size )
D′+ < C′+ ( size )
∴ C statement is incorrect.

(76) Given below are two statements:

Statement (I) : The 4f and 5f - series of elements are placed separately in the Periodic table to preserve the
principle of classification.
Statement (II) :S-block elements can be found in pure form in nature. In the light of the above statements, choose
the most appropriate answer from the options given below : [JEE MAIN 2024]
(A) Statement I is false but Statement II is true (B) Both Statement I and Statement II are true
(C) Statement I is true but Statement II is false (D) Both Statement I and Statement II are false

26
 Solution:(Correct Answer:C)
s-block elements are highly reactive and found in combined state.

(77) Number of elements from the following that CAN N OT form compounds with valencies which match with their
respective group valencies is
B, C, N, S, O, F, P, Al, Si [JEE MAIN 2024]

(A) 7 (B) 5 (C) 6 (D) 3

Solution:(Correct Answer:D)
N, O, F can’t extend their valencies upto their group number due to the non-availability of vacant 2d like orbital.

(78) Given below are two statements:

Statement I : The metallic radius of Na is 1.86 A◦ and the ionic radius of Na+ is lesser than 1.86 A◦ .
Statement II : Ions are always smaller in size than the corresponding elements.
In the light of the above statements, choose the correct answer from the options given below : [JEE MAIN 2024]
(A) Statement I is correct but Statement II is false (B) Both Statement I and Statement II are true
(C) Both Statement I and Statement II are false (D) Statement I is incorrect but Statement II is true

Solution:(Correct Answer:A)
rNa > rNa+
So, Statement (I) is correct but size of anions are greater than size of neutral atoms.
So statement (II) is incorrect.

5
(79) Identify the element for which electronic configuration in +3 oxidation state is [Ar]3 d : [JEE MAIN 2021]

(A) Ru (B) M n (C) Co (D) Fe

Solution:(Correct Answer:D)

s
as
5
Fe3+ [Ar]3 d

(80) The correct order of increasing ionic radii is .... . [JEE MAIN 2022]

(A) M g 2+ < N a+ < F − < O 2− < N 3− (B) N 3− < O 2− < F − < N a+ < M g 2+
cl

(C) F − < N a+ < O 2− < M g 2+ < N 3− (D) N a+ < F − < M g 2+ < O 2− < N 3−

Solution:(Correct Answer:A)
d

N −3 > O −2 > F − > N a+ > M g +2 ( Radii )

(Isoelectronic species)
Ve

(81) Among the statements (I − IV ), the correct ones are:

(I) Be has smaller atomic radius compared to M g
(II) Be has higher ionization enthalpy than Al.
(III) Charge/radius ratio of Be is greater than that of Al.
(IV ) Both Be and Al form mainly covalent compounds. [JEE MAIN 2020]
(A) (I), (II) and (IV ) (B) (II), (III) and (IV ) (C) (I), (II) and (III) (D) (I), (III) and (IV )

Solution:(Correct Answer:C)
I, AN : Be < M g
II IE : Be > Al
III Charge/radius ratio of Be w less than that of Al
IV Be, Al mainly form covalent compounds

(82) For electron gain enthalpies of the elements denoted as ∆eg H, the incorrect option is : [JEE MAIN 2023]

(A) ∆eg H(Cl) < ∆eg H(F ) (B) ∆eg H(Se) < ∆eg H(S) (C) ∆eg H(I) < ∆eg H(At) (D) ∆eg H(T e) < ∆eg H (Po)

Solution:(Correct Answer:B)
(1) ∆eg H(Cl) < ∆eg H(F )
(−345)(−328) Correct
(2) ∆eg H(Se) < ∆eg H(S)
(−195) (−200) Incorrect
(3) ∆eg H(I) < ∆eg H(At)
(−295)(−270) Correct
(4) ∆eg H(T e) < ∆eg H(P o)
(−190)(−183) Correct

27
(83) Three elements X, Y and Z are in the 3rd period of the periodic table. The oxides of X, Y and Z, respectively, are
basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is [JEE MAIN 2020]
(A) Z < Y < X (B) X < Z < Y (C) X < Y < Z (D) Y < X < Z

Solution:(Correct Answer:C)
When we are moving from left to right in a periodic table acidic character of oxides increases (as well as atomic
number of atom increases)
X<Y <Z
X < Y < Z (atomic number)

(84) When the first electron gain enthalpy (∆eg H) of oxygen is −141 kJ/mol, its second electron gain enthalpy is [JEE MAIN
2019]
(A) a more negative value than the first (B) almost the same as that of the first
(C) negative, but less negative than the first (D) a positive value

Solution:(Correct Answer:D)
2nd electron gain enthalpy of oxygen is positive.

(85) The atomic number of Unnilunium is........... [JEE MAIN 2020]

(A) 101 (B) 95 (C) 98 (D) 106

Solution:(Correct Answer:A)
Unnilunium ⇒ 101

(86) The correct order of electronegativity for given elements is: [JEE MAIN 2023]

(A) C > P > At > Br (B) Br > P > At > C (C) P > Br > C > At (D) Br > C > At > P

Solution:(Correct Answer:D)

s
Atom E.N
as
Br 3.0
C 2.5
cl
At 2.2
P 2.1
d

(87) Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The first ionization enthalpy for oxygen is lower than that of nitrogen.
Ve

Reason R : The four electrons in 2p orbitals of oxygen experience more electron-electron repulsion.
In the light of the above statements, choose the correct answer from the options given below. [JEE MAIN 2022]
(A) Both A and R are correct and R is the correct (B) Both A and R are correct but R is NOT the correct
explanation of A. explanation of A.
(C) A is correct but R is not correct. (D) A is not correct but R is correct

Solution:(Correct Answer:A)
Ionisation energy = N > O.
In oxygen atom, 2 of the 42p electrons must occupy the same 2p orbital resulting in an increased electron
electron-repulsion.

(88) Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Metallic character decreases and non-metallic character increases on moving from left to right in a
period.
Reason (R) : It is due to increase in ionisation enthalpy and decrease in electron gain enthalpy, when one moves
from left to right in a period.
In the light of the above statements, choose the most appropriate answer from the options given below : [JEE MAIN
2021]

(A) (A) is false but (R) is true.

(B) (A) is true but (R) is false
(C) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(D) Both (A) and (R) are correct but (R) is not the correct explanation of (A)

28
 Solution:(Correct Answer:B)
From left to right in periodic table :-
Metallic character decreases
Non-metallic character increases
⇒ It is due to increase in ionization enthalpy and increase in electron gain enthalpy.

(89) The correct order of the ionic radii of

O2− , N 3− , F − , M g 2+ , N a+ and Al3+ is [JEE MAIN 2020]
(A) Al3+ < N a+ < M g 2+ < O 2− < F − < N 3− (B) N 3− < O 2− < F − < N a+ < M g 2+ < Al3+
(C) Al3+ < M g 2+ < N a+ < F − < O 2− < N 3− (D) N 3− < F − < O 2− < M g 2+ < N a+ < Al3+
Solution:(Correct Answer:C)
Correct order of size for isoelectronic species.
Al3+ < M g 2+ < N a+ < F − < O 2− < N 3−

(90) The increasing order of the atomic radii of the following elements is
(a) C (b) O (c) F (d) Cl (e) Br [JEE MAIN 2020]
(A) (b) < (c) < (d) < (a) < (e) (B) (a) < (b) < (c) < (d) < (e)
(C) (d) < (c) < (b) < (a) < (e) (D) (c) < (b) < (a) < (d) < (e)
Solution:(Correct Answer:D)
If the given elements are arranged according to their position in periodic table Atomic radius
C > O > F < Cl < Br
Br > Cl > C > O > F

(91) The atomic number of the element unnilennium is [JEE MAIN 2020]

s
(A) 119 (B) 108 (C) 102 (D) 109
Solution:(Correct Answer:D)
as
109
un nil enn
Hence correct name → unnilennium
cl
(92) The correct order of electron affinity is [JEE MAIN 2018]
(A) O > F > Cl (B) F > O > Cl (C) F > Cl > O (D) Cl > F > O
d

Solution:(Correct Answer:D)
On moving from left to right across a period, the electron affinity becomes more negative. On moving from top to
Ve

bottom in a group, the electron affinity becomes less negative. Chlorine has more negative electron affinity than
fluorine, Because adding an electron to fluorine (2p orbital) causes greater repulsion than adding an electron to
chlorine (3p orbital) which is larger in size

(93) Given below are two statements:

Statement (I) : Both metal and non-metal exist in p and d-block elements.
Statement (II) : Non-metals have higher ionisation enthalpy and higher electronegativity than the metals.
In the light of the above statements, choose the most appropriate answer from the option given below: [JEE MAIN 2024]
(A) Both Statement I and Statement II are false (B) Statement I is false but Statement II is true
(C) Statement I is true but Statement V II is false (D) Both Statement I and Statement II are true
Solution:(Correct Answer:B)
I. In p−Block both metals and non metals are present but in d-Block only metals are present.
II. EN and IE of non metals are greater than that of metals
I - False, II-True

(94) The first ionisation potential of N a is 5.1 eV. The value of electron gain enthalpy of N a+ will be : ............... eV [JEE
MAIN 2013]

(A) −2.55 (B) −5.1 (C) −10.2 (D) +2.55

Solution:(Correct Answer:B)
Na → Na+ + e− IE = 5.1eV . . . . . .
Na+ + e− → Na
Second reaction is inverse of first reaction,
therefore electron goes enthalapy of N a+
is reverse of ionization energy
∴ ∆Heg = −5.1eV

29
(95) The correct order of metallic character is: [JEE MAIN 2023]

(A) Be > Ca > K (B) Ca > K > Be (C) K > Ca > Be (D) K > Be > Ca

Solution:(Correct Answer:C)
On moving from top to bottom metallic character increases while on moving from left to right metallic decreases.
K > Ca > Be

(96) The correct order of first ionization enthalpy values of the following elements is:
(A) O (B) N (C) Be (D) F (E) B
Choose the correct answer from the options given below : [JEE MAIN 2024]

(A) B < D < C < E < A (B) E < C < A < B < D (C) C < E < A < B < D (D) A < B < D < C < E

Solution:(Correct Answer:B)
Correct order of Ist IE

(97) Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason(R) :
Assertion (A) : The ionic radii of O2− and M g 2+ are same.
Reason (R) : Both O2− and M g 2+ are isoelectronic species.
In the light of the above statements, choose the correct answer from the options given below [JEE MAIN 2022]
(A) Both (A) and (R) are true and (R) is the correct explanation of (A)
(B) Both (A) and (R) are true but (R) is not the correct explanation of (A)

s
(C) (A) is true but (R) is false
(D) (A) is false but (R) is true
as
Solution:(Correct Answer:D)
Ionic radius of O2− is more than that of M g 2+
Both O2− and M g 2+ are isoelectronic with 10 electrons
cl

(98) In comparison to boron, berylium has [JEE MAIN 2019]

(A) greater nuclear charge and greater first ionisation
d

(B) lesser nuclear charge and lesser first ionisation

enthalpy enthalpy
Ve

(C) greater nuclear charge and lesser first ionisation (D) lesser nuclear charge and greater first ionisation
enthalpy enthalpy

Solution:(Correct Answer:D)
Since boron has higher nuclear charge because it has greater atomic number and lower 1st I.E. then beryllium
due to fully filled s− orbital.

(99) Match List I with List II

List-I (Elements) List-II(Properties in their respective groups)
A Cl, S I Elements with highest electronegativity
B Ge, As II Elements with largest atomic size
C Fr, Ra III Elements which show properties of both
metals and non metal
D F, O IV Elements with highest negative electron
gain enthalpy

Choose the correct answer from the options given below : [JEE MAIN 2024]
(A) A − II, B − III, C − IV, D − I (B) A − III, B − II, C − I, D − IV
(C) A − IV, B − III, C − II, D − I (D) A − II, B − I, C − IV, D − III

Solution:(Correct Answer:C)
Elements with highest electronegativity → F, O
Elements with largest atomic size → Fr, Ra
Elements which shows properties of both metal and non-metals i.e. metalloids → Ge, As
Elements with highest negative electron gain enthalpy → Cl, S

30
(100) The pair that has similar atomic radii is [JEE MAIN 2019]
(A) T i and Hf (B) M n and Re (C) Sc and N i (D) M o and W

Solution:(Correct Answer:D)
Due to lanthanoide contraction M o and W have similar atomic radii.

(101) if IU P AC name of an element is ′ U nununnium′ then the element belongs to nth group of periodic table. The value
of n is______ [JEE MAIN 2024]
(A) 8 (B) 15 (C) 10 (D) 11

Solution:(Correct Answer:D)
111 belongs to 11th group

(102) Which of these statements is not true [JEE MAIN 2014]

(A) N O+ is isoelectronic with O2
(B) B is always covalent in its compounds
(C) In aqueous solution, the T i+ ion is much more stable than T i(III)
(D) LiAlH4 is a versatile reducing agent in organic synthesis

Solution:(Correct Answer:A)
(a) N O + = 7 + 8 − 1 = 14 e− . O2 = 16 e− . i.e. not isoelectronic
(b) Boron forms only covalent compounds. This is due to its extremely high ionisation energy.
(c) Compounds of T i+ are much more stable than those of T i3+ .
(d) LiAlH4 is a versatile reducing agent in organic synthesis

(103) Which of the following represents the correct order of metallic character of the given elements ?

s
[JEE MAIN 2023]

(A) Si < Be < M g < K (B) Be < Si < M g < K (C) K < M g < Be < Si (D) Be < Si < K < M g
as
Solution:(Correct Answer:A)
Metallic character increases down the group and decreases along the period.
cl
(104) Similarity in chemical properties of the atoms of elements in a group of the Periodic table is most closely related to
[JEE MAIN 2014]
(A) atomic numbers (B) atomic masses
d

(C) number of principal energy levels (D) number of valence electrons

Solution:(Correct Answer:A)
Ve

If elements are arranged in order of their increasing atomic numbers, element coming at intervals of
2, 8, 8, 18, 18, 32 and 32 will have similar physical and chemical properties and thus grouped in one particular group.

(105) The correct order of density is [JEE MAIN 2022]

(A) Be > M g > Ca > Sr (B) Sr > Ca > M g > Be
(C) Sr > Be > M g > Ca (D) Be > Sr > M g > Ca

Solution:(Correct Answer:C)
In II ′ A′ group density decreases down the group till Ca and after that it increases.Correct order of density is
Sr > Be > M g > Ca

(106) Identify the correct statements about p-block elements and their compounds.
(A) Non metals have higher electronegativity than metals.
(B) Non metals have lower ionisation enthalpy than metals.
(C) Compounds formed between highly reactive nonmetals and highly reactive metals are generally ionic.
(D) The non-metal oxides are generally basic in nature.
(E) The metal oxides are generally acidic or neutral in nature. [JEE MAIN 2024]

(A) (D) and (E) only (B) (A) and (C) only (C) (B) and (E) only (D) (B) and (D) only

Solution:(Correct Answer:B)
As electronegativity increases non-metallic nature increases.
Along the period ionisation energy increases.
High electronegativity difference results in ionic bond formation.
Oxides of metals are generally basic and that of non-metals are acidic in nature.

31
(107) The five successive ionization enthalpies of an element are 800, 2427, 3658, 25024 and 32824 kJmol−1 . The number of
valence electrons in the element is [JEE MAIN 2020]
(A) 2 (B) 3 (C) 4 (D) 5

Solution:(Correct Answer:B)
Let suppose element X ⇒
+ +2
IE IE IE
X(g) −−→
1
X (g) −−−→
2
X( g) −−−→
3

800 2427 3658

+3
IE +4 IE +5
x (g) −−−4→ X( g ) −−−5→ X( g )
25024 32824
X +3 has stable inert gas configuration as there is high jump after IE 3
So valence electrons are 3

(108) Which of the following statements are not correct?

A. The electron gain enthalpy of F is more negative than that of Cl
B. Ionization enthalpy decreases in a group of periodic table
C. The electronegativity of an atom depends upon the atoms bonded to it.
D. Al2 O3 and N O are examples of amphoteric oxides.
Choose the most appropriate answer from the options given below: [JEE MAIN 2023]
(A) A, B, C and D (B) A, C and D Only (C) B and D Only (D) A, B and D Only

Solution:(Correct Answer:B)
Electronegativity of an element depends on the atom with which it is attached.
N O = neutral oxide
Al2 O3 = amphoteric oxide

(109) Incorrect statements among the following is/are

(A) 2nd electron gain enthalpy is always endothermic
(C) Al2 O3 and BeO are amphoteric oxide
s
(B) Electronegativity is the property of bonding atoms
(D) None of these are incorrect
as
Solution:(Correct Answer:D)

(110) Find exothermic reaction

cl
−
(A) F(g) → F(g) + e− (B) Be(g) + e− → Be−
(g)
−
(C) O(g) + e− → O(g) −2
(D) O(g) + 2e− → O(g)

Solution:(Correct Answer:C)
d

(111) The statement that is not correct for the periodic classification of elements is [IIT 1992]
Ve

(A) The properties of elements are the periodic functions of their atomic numbers
(B) Non-metallic elements are lesser in number than metallic elements
(C) The first ionisation energies along a period do not vary in a regular manner with increase in atomic number
(D) For transition elements the d-sub-shells are filled with electrons monotonically with increase in atomic
number

Solution:(Correct Answer:C)
It’s Obvious

(112) Assertion : Electron affinity refers to an isolated atom’s attraction for an additional electron while electronegativity
is the ability of an atom of an element to attract electrons towards itself in a shared pair of electrons.
Reason : Electron affinity is a relative number and electronegativity is experimentally measurable. [AIIMS 2010]
(A) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
(B) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
(C) If the Assertion is correct but Reason is incorrect.
(D) If both the Assertion and Reason are incorrect.

Solution:(Correct Answer:C)
Assertion is true but Reason is false. Electron affinity is experimentally measurable while electronegativity is a
relative number.

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(113) Choose the correct order for given property
(M.P. → M eltingP oint; S → Solubility)
M.P. CaF2 > M gF2 > BeF2 ; M.P. CaO > BeO > M gO;
(A) S M gF2 < CaF2 < BeF2 (B) S BeO < M gO < CaO

M.P. AgCl < KCl < N aCl; M.P. AgCl > KCl > N aCl;
(C) S AgCl < N aCl > KCl (D) S KI > LiI > N aI

Solution:(Correct Answer:A)

(114) Chloride of an element A gives neutral solution in water. In the periodic table, the element A belongs to [AIIMS 1992]
(A) First group (B) Third group (C) Fifth group (D) First transition series

Solution:(Correct Answer:A)
(a) First group e.g. N aCl + H2 O ⇌ N aOH + HCl

(115) What is the atomic number of the element with the maximum number of unpaired 4p electrons
(A) 33 (B) 26 (C) 23 (D) 15

Solution:(Correct Answer:A)
Max unpaired e− s in p− Subshell belong to ′ N ′ family.

(116) For valence shell of N a screening by

(A) 1s orbital (B) 2s orbital (C) 2p orbital (D) All

Solution:(Correct Answer:D)
Because for valence shell screening by all inner electrons.
s
as
∴ 1s2 2s2 2p6 3s2

(117) The heaviest atom amongst the following is

(A) U (B) Ra (C) P b (D) Hg
cl

Solution:(Correct Answer:A)
(a) U > Ra > P b > Hg
d

(118) Correct order of acidic strength

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(A) HF > HCl > HBr > HI (B) H3 P O2 > H3 P O3 > H3 P O4

(C) B(OH)3 > H2 CO3 > HN O3 (D) H2 O > H2 S > H2 Se > H2 T e

Solution:(Correct Answer:B)

(119) Which one of the following elements has the highest ionisation energy [IIT 1990]
(A) [N e] 3s2 3p1 (B) [N e] 3s2 3p2 (C) [N e] 3s2 3p3 (D) [Ar] 3d10 4s2 4p2

Solution:(Correct Answer:C)
(c) Since e− is to be removed from exactly half filled p-orbital.

(120) The process requiring absorption of energy is

(A) N → N − (B) F → F − (C) Cl → Cl− (D) H → H −

Solution:(Correct Answer:A)
(a) Nitrogen has stable 2p3 configuranon and also due to high e− charge density at outermost orbital it requires
energy to add one extra e− in its outer most shell i.e., its first electron gain enthalpy is positive

(121) Which of the following set has highest sum of IE indica ted as compared to all other sets mentioned
(A) IE1 of He, IE2 of Li, IE2 of Ca (B) IE1 of He , IE2 of Li, IE3 of M g
(C) IE1 of Li, He and K (D) IE2 of N a, Ba and Sr

Solution:(Correct Answer:B)
By losing 1 and 2 electrons respectively. Li & M g acquire noble gas configuration.

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(122) The incorrect statement among the following is
(A) The first ionization potential of Al is less than the first ionization potential of M g
(B) The second ionization potential of M g is greater than the second ionization potential of N a
(C) The first ionization potential of N a is less than the first ionization potential of M g
(D) The third ionization potential of M g is greater than the third ionization potential of Al

Solution:(Correct Answer:B)
After removal of an electron sodium acquires stable noble gas configuration. It is difficult to remove electron
from stable noble gas configuration species. Therefore, second ionization potential of M g is less than that of N a.

(123) The order of the magnitude of first ionisation potentials of Be, B, N and O is
(A) N > O > Be > B (B) N > Be > O > B (C) Be > B > N > O (D) B > Be > O > N
Solution:(Correct Answer:A)
(a) N > O > Be > B Ist ionisation energy of (n) because of half filled p-orbital.

(124) Arrange the following in increasing order of their atomic radius : N a, K, M g, Rb

(A) M g < K < N a < Rb (B) M g < N a < K < Rb (C) M g < N a < Rb < K (D) N a < K < Rb < M g
Solution:(Correct Answer:B)
It’s Obvious

(125) Hydrogen by donating one electron forms H + . In this property, it resembles with
(A) Transitional metals (B) Alkaline earth metals (C) Alkali metals (D) Halogens
Solution:(Correct Answer:C)

s
(c) As alkali metals have tendency to loose e− .
as
(126) Which of the following may act as an oxidising and reducing agent both?
(A) K2 Cr2 O7 (B) SO2 (C) H2 S (D) N H3
Solution:(Correct Answer:B)
cl
Substance can acts as both oxidizing as well as reducing agent when a metal atom is present in its intermediate
step.
O3 can acts as only oxidizing agent due to its unstable nature and decomposes to give nascent oxygen.
d

HN O3 : Nitrogen is present in its highest oxidation state i.e., +5 so it can act as only oxidizing agent.
SO2 :Sulphur is present in +4 oxidation state so it can act as both oxidizing as well as reducing agent.
Ve

(127) Which of the following isoelectronic series would lose an electron most easily ?
(A) S 2− (B) Cl− (C) Ar (D) K +
Solution:(Correct Answer:A)

(128) The correct order of ionisation energy of C, N, O, F is :-

(A) F < N < C < O (B) C < N < O < F (C) C < O < N < F (D) F < O < N < C
Solution:(Correct Answer:C)
The correct order of ionization energy of C, N, O&F is C < O < N < F .
In a period on moving from left to right, the ionization energy increases.
This is due to increase in the effective nuclear charge.
However the ionization energy of O is lower than the ionization energy of N .
This is because in case of N an electron is to be removed from stable half filled 2p sub-shell which requires large
energy.

(129) Which of the following arrangements shows the correct order of decreasing paramagnetism?
(A) N > Al > O > Ca (B) N > O > Al > Ca (C) O > N > Al > Ca (D) O > N > Ca > Al
Solution:(Correct Answer:B)

(130) Which of the following statement is not correct for the element having electronic configuration 1s2 , 2s2 p6 , 3s1
(A) It is a monovalent electropositive (B) It forms basic oxide
(C) It is a non-metal (D) It has low electron affinity
Solution:(Correct Answer:C)
It is a metal. Since it has tendency to lose an electron inorder to attain stable configuration.

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(131) Astatine is a
(A) Halogen (B) Rare earth element (C) Alkaline earth metal (D) None of these

Solution:(Correct Answer:A)
(a) Elements of group halogen are : F, Cl, Br I and At.

(132) When magnesium burns in air, compounds of magnesium formed are magnesium oxide and
(A) M g3 N2 (B) M gCO3 (C) M g(N O3 )2 (D) M gSO4

Solution:(Correct Answer:A)
When magnesium burns in air it forms magnesium nitride with nitrogen and with oxygen it forms magnesium
oxide.

(133) Order of first ionization potentials of elements Li, Be, B, N a is

(A) Li > Be > B > N a (B) Be > B > Li > N a (C) N a > Li > B > Be (D) Be > Li > B > N a

Solution:(Correct Answer:B)
(b) Ionization potential increases as we go from left to right in a period, while it decreases as we come down a
group.
Be B Li N a
9.3 8.3 5.4 5.1

(134) Which one of the following species possesses maximum size

(A) N a+ (B) F − (C) N e (D) O2−

Solution:(Correct Answer:D)
(d) All are isoelectronic but O2− has lowest charge among them. So it is largest in size.

s
(135) Which set has the same number of unpaired electrons in their ground state
as
(A) Cl− , F e3+ , Cr3+ (B) N a+ , M g 2+ , Al (C) N a, P, Cl (D) N, P, V

Solution:(Correct Answer:D)
(d) N and P have 3 unpaired electrons in 2p and 3p respectively; V has 3 unpaired electrons in 3d.
cl

x 5 eV
(136) N a− ←
− N a −−−→ N a+
Predict the value of ′ X ′ is .............. eV
d

(A) 5 (B) 8 (C) 3 (D) Date insufficient

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Solution:(Correct Answer:C)
For any element IP > EA

(137) Which of the following has minimum ionization energy

(A) Ge (B) Se (C) As (D) Br

Solution:(Correct Answer:A)
(a) I.E. increases from left to right in a period.

(138) Which ionisation potential (IP ) in the following equations involves the greatest amount of energy
(A) N a → N a+ + e− (B) K + → K 2+ + e− (C) C 2+ → C 3+ + e− (D) Ca+ → Ca2+ + e−

Solution:(Correct Answer:B)
(b)K + → K 2+ + e− . Since e− is to be removed from stable configuration.

(139) Mosley’s name is most closely associated with the discovery of

(A) Positron (B) Deutrons (C) Atomic number (D) Atomic weight

Solution:(Correct Answer:C)
It’s Obvious

(140) Which has the highest second ionisation potential [AIIMS 1991]
(A) Nitrogen (B) Carbon (C) Oxygen (D) Fluorine

Solution:(Correct Answer:C)
(c) In second transition electron is to be removed from half filled orbital.

35
(141) Consider the following electronic configuration of an element (P ) :
[Xe]4f 14 5d1 6s2
Then correct statement about element ′ P ′ is
(A) It belongs to 6th period and 1st group (B) It belongs to 6th period and 2nd group
(C) It belongs to 6th period and 3rd group (D) None of these

Solution:(Correct Answer:C)
(c) [Xe] 4f 14 5d1 6s2
Atomic number = 71 Period number = 6th Group number = 3rd

(142) A neutral atom will have the lowest ionization potential when its electronic configuration is [AIPMT 1991]
(A) 1s1 (B) 1s2 , 2s2 p6 (C) 1s2 , 2s2 p2 (D) 1s2 , 2s2 p6 , 3s1

Solution:(Correct Answer:D)
(d) Ionization potential is least for alkali metals and it decreases down the group.

(143) Consider the following information about element P and Q

Period number Group number
Q 2 15
P 3 2
Then formula of the compound formed by P and Q element is
(A) P Q (B) P3 Q2 (C) P2 Q3 (D) P Q2

Solution:(Correct Answer:B)
P is trivalent non-metal Q is divalent metal hence formula of the compound is P2 Q3

(144) Strongest acid is

(A) Al2 O3 (B) M gO
s
(C) N a2 O (D) CaO
as
Solution:(Correct Answer:A)
(a) The basic nature of oxide decreases across the period as metallic character decreases. Therefore acidic nature
of oxide increases.
cl

(145) Highest density is of . . . . . . . . . .

(A) Ir (B) Os (C) P b (D) Hg
d

Solution:(Correct Answer:B)
Ve

Of all the metals, Osmium has the highest density of 22.59 gm/cm3 .

(146) Which one of the following elements shows both positive and negative oxidation states?
(A) Cesium (B) Fluorine (C) Iodine (D) Xenon

Solution:(Correct Answer:C)
The atomic size of Iodine is very big and it has empty d orbitals to expand it’s electron in s and p orbitals In 3rd
excited state iodine has 7 unpaired electrons so it can show positive oxidation state with higher electronegative
element like Cl, Br, F . Generally all halogens exhibit negative oxidation state due to their electronegativity.

(147) The electronic configuration of an atom A is 1s2 , 2s2 p6 , 3s2 p6 d10 , 4s2 p3 . The chemistry of A is therefore likely to be
similar to that of
(A) Chlorine (B) Nitrogen (C) Oxygen (D) Boron

Solution:(Correct Answer:B)
Nitrogen has similar electronic configuration since it has its valence electrons in 2s2 2p3

(148) In which of the following groups all the three members are of the alkaline earth metals family
(A) Al, Sr, T i (B) Li, N a, K (C) M g, Ba, Ca (D) Rb, Cs, F r

Solution:(Correct Answer:C)
(c) M g, Ba, Ca have ns2 configuration.

(149) In the periodic table, metallic character of the elements shows which one of the following trends?
(A) Decreases down the group and increases across the (B) Increases down the group and decreases across the
period period
(C) Increase across the period and also down the group (D) Decreases across the period and also down the group

36
 Solution:(Correct Answer:B)
Metallic character decreases as you move across a period in the periodic table from left to right. This occurs as
atoms more readily accept electrons to fill a valence shell than lose them to remove the unfilled shell. Metallic
character increases as you move down an element group in the periodic table

(150) Which of the following element does not occur in liquid form
(A) Hg (B) Li (C) Ga (D) Br

Solution:(Correct Answer:B)
Lithium is solid at room temperature and rest all other elements exist as liquids at room temperature.

s
as
d cl
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