1. An atom has an atomic weight of W and atomic 12.

Number of electron in –CONH2 are -

number N then – [1] 22 [2] 23 [3] 24 [4] 20
[1] Number of electrons = W – N 13. The hydride ion is isoelectronic with -
+ +
[2] Number of protons = W – N [1] H [2] He [3] He [4] Be
[3] Number of neutrons = W – N 14. Which of the following salt has isoelectronic cation
and anion -
[4] Number of neutrons = N
[1] KF [2] NaCl [3] SrCl2 [4] MgF2
2. An element having atomic number 25 and atomic
15. Number of electrons in nucleus of an element of atomic
weight 55 will have –
number 14 is -
[1] 25 protons and 30 neutrons
[1] Zero [2] 14 [3] 7 [4] 20
[2] 25 neutrons and 30 protons 16. The increasing order (lowest first) for the value of e/
[3] 55 protons m (charge/mass) is for -
[4] 55 neutrons [1] e, p, n,  [2] n, p, e, 
3. The electrons, protons and neutrons were discovered, [3] n, p, , e [4] n, , p, e
2+ 3+
respectively by – 17. Li and Be are -
[1] James Chadwick, John Dalton and J. J. Thomson [1] Isotopes [2] Isobars [3] Isoelectronic [4] None
[2] J. J. Thomson, Goldstein and James Chadwick 18. X-rays are -
[1] Electrons [2] Protons
[3] James Chadwick, Goldstein and J. J. Thomson
[3] Light waves of small wavelength
[4] Rutherford, John Dalton and J. J. Thomson
[4] Light waves of high wavelength
4. How many neutrons are present in the nucleus of
226 19. Isodiapheres have –
88Ra –
[1] The same number of neutrons but different number
[1] 88 [2] 226 [3] 140 [4] 138 of protons
5. Charge on a positron is equal to that of - [2] The same number of (Proton – Electron)
[1] Proton [2] Electron [3] Nucleon [4] Neutron [3] The same radius of nucleus sphere
6. Which one of the following pairs represents isobars- [4] The same number of (Neutrons – Protons)
3 4 24 25 20
[1] 2He and 2He [2] 12Mg and 12Mg 20. Atomic weight of Ne is 20.2. Ne is a mixture of Ne
22
[3]
40 39 40 40 and Ne . Relative abundance of heavier isotope is –
19K and 19K [4] 19K and 18Ar
[1] 90 [2] 20 [3] 40 [4] 10
7. Atomic weight of an element is not a whole number
21. The atom A, B, C have the configuration
because –
A [Z(90), A(146)], B [Z(92), A(146)], C[Z(90) ,
[1] It contains electrons, protons & neutrons
A(148)] So that–
[2] It contains allotropic forms (a) A and C – Isotones (b) A and C – Isotopes
[3] It contains isotopes (c) A and B – Isobars (d) B and C– Isobars
[4] None of the above (e) B and C – Isotopes
8. Which of the following are isoelectronic – Which of the above is true –
+ +
[1] Na and Ne [2] K and O [1] a, b only [2] b & c only
[3] Ne and O [4] Na and K
+ + [3] a, c, d only [4] a, c, e only
54 56 57 58
9. Which of the following is isoelectronic with N2O – 22. (i) 26Fe , 26Fe , 26Fe , 26Fe (a) Isotopes
3 3
(ii) 1H , 2He (b) Isotones
[1] NO [2] N2O5 [3] CO2 [4] CO 76 77
(iii) 32Ge , 33As (c) Isodiaphers
10. Which of the following pair having same number of 235 231
(iv) 92U , 90Th (d) Isobars
electron – 1 2 3
+ – (v) 1H , 1D , 1T
[1] Al , N2 [2] CN , N2
Match the above correct terms –
[3] Both [1] & [2] [4] CO , H2O
[1] [(i), – a], [(ii) – d], [(iii) – b], [(iv) – c], [(v) – a]
11. The sum of number of protons and neutrons in an [2] [(i) – a], [(ii) – d], [(iii) – d], [(iv) – c], [(v) – a]
isotope of hydrogen is –
[3] [(v) – a], [(iv) – c], [(iii) – d], [(ii) – b], [(i) – a]
[1] 6 [2] 5 [3] 4 [4] 3 [4] None of them
 76
23. An isotone of 34. Assume that the nucleus of the F–atom is a sphere
32 Ge is -
–13
[1]
77 87 77 78 of radius 5 × 10 cm. What is the density of matter
32Ge [2] 33As [3] 34Se [4] 34Se
in F–nucleus
24. Millikan's oil drop experiment is used to find - 11 13
[1] 6.02 × 10 g/ml [2] 6.02 × 10 g/ml
[1] e/m ratio of an electron 18
[3] 6.02 × 10 g/ml [4] None
[2] Charge on an electron
35. Assuming the nucleus and an atom to be spherical,
[3] Mass of an electron
the radius of the nucleus of mass number A is given
[4] Velocity of an electron –13 1/3
by 1.25 × 10 × A cm. The atomic radius of atom
25. Anode rays were discovered by - is 1Å. If the mass number is 64, the fraction of the
[1] Gold stein [2] J. Stoney atomic volume that is occupied by the nucleus is –
–13 –13
[3] Rutherford [4] J.J. Thomson [1] 1.25 × 10 [2] 2.50 × 10
–5
26. Isotopes were discovered by - [3] 5 × 10 [4] None
[1] Aston [2] Soddy 36. The energy difference between two electronic states
is 43.56 kcal/mole. The frequency of light emitted when
[3] Thomson [4] Millikan
electron drops. from higher orbit to lower orbit, is-
27. Number of protons, neutrons and electrons present in [Planck's constant = 9.52 × 10
–14
k cal sec./mole]
32
15P are - 14 14
[1] 9.14 × 10 cycles/sec [2] 45.7 × 10 cycles/sec
[1] 15p, 17n, 15e [2] 17 p, 17 n, 15 e 14 14
[3] 91.4 × 10 cycles/sec [4] 4.57 × 10 cycles/sec
[3] 15p, 15n, 15e [4] 15 p, 15 n, 17 e
37. The radius of hydrogen in ground state is 0.53 A°. In
28. The e/m is not constant for - 2+
normal state the radius of Li (atomic number = 3)
[1] Cathode rays [2] Positive rays in ground state will be –
[3] -rays [4] -rays [1] 1.06 A° [2] 0.265 A° [3] 0.17 A° [4] 0.53 A°
–12
29. Radius of the nucleus is equal to 10 cm. and that 38. The ratio of the velocity of the electron in the third and
–8 +
of the atom is equal to 10 cm. What is the fraction fifth shell for He would be –
of the volume of the atom occupied by nucleus – [1] 5 : 3 [2] 1 : 2 [3] 3 : 5 [4] 3 : 4
12 –12 –20 –4
[1] 10 [2] 10 [3] 10 [4] 10 39. The ratio of velocity of electron for the system : H[first
+ +2
30. According to classical theory if an electron is moving orbit], He [second orbit] and Li [third orbit] would
in a circular orbit around the nucleus- be –
[1] It will continue to do so for sometime. [1] 1 : 1 : 1 [2] 1 : 2 : 3 [3] 3 : 2 : 1 [4] 2 : 3 : 1
+ +2 +3
[2] Its orbit will continuously shrink. 40. He , Li , and Be will have the same velocity of
[3] Its orbit will continuously enlarge. electron in the orbit for the three species –
[4] It will continue to do so for all the time. [1] 1, 2, 3 [2] 2, 3, 4 [3] 3, 2, 4 [4] 3, 4, 5
31. Which one of the following is not the characteristic of 41. The electronic velocity in the fourth Bohr orbit of
Planck's quantum theory of radiation- hydrogen is v. The velocity of the electron in the first
[1] The energy is not absorbed or emitted in whole orbit would be –
number multiple of quantum. [1] 4v [2] 16v [3] v/4 [4] v/16
th th
[2] Radiation is associated with energy. 42. Difference between n and (n + 1) Bohr's radius of
th
[3] Radiation energy is not emitted or absorbed 'H' atom is equal to it's (n – 1) Bohr's radius. The value
continously but in the form of small packets called of n is –
quanta or photon. [1] 1 [2] 2 [3] 3 [4] 4
[4] This magnitude of energy associated with a 43. Circumference of the first orbit of hydrogen atom is
quantum is proportional to the frequency.  h2 
given by the formula a 0  4 2me 2 
32. Calculate the energy of a photon of light having  
15 –1
frequency of 1.0 × 10 sec . 22 a 0
Planck's constant h = 6.63 × 10
–34 [1] a0 [2] [3] 4 a0 [4] a0
7 2
–18 –19
[1] 6.63 × 10 J [2] 6.63 × 10 J 44. If r1 is the radius of the first orbit of hydrogen atom,
–15 –12
[3] 6.63 × 10 J [4] 6.63 × 10 J then the radii of second, third and fourth orbits in terms
33. The Bohr's model of hydrogen atom is not applicable of r1 are–
2 3 4
to - [1] r1 , r1 , r1 [2] 8r1, 27r1, 64r1
+ +1
[1] H2 [2] He [3] He [4] D [3] 4r1, 9r1 16r1 [4] 2r1, 6r1, 8r1
45. Bohr’s radius of N shell is - 56. The KE of electron in He will be maximum in -
rd nd
[1] 8.48 Å [2] 0.53 Å [3] 4.77 Å [4] None [1] 3 orbit [2] 2 orbit
st
46. The distance between second and third Bohr's orbit [3] 1 orbit [4] In orbit with n = 
of hydrogen atom is – 57. The minimum energy required to excite a hydrogen
[1] 0.529 Å [2] 1.058 Å [3] 2.116 Å [4] 2.645 Å atom from its ground state is -
st
47. The speed of the electron in the 1 orbit of the [1] 3.4 eV [2] 13.6 eV
hydrogen atom in the ground state is [c is the velocity [3] –13.6 eV [4] 10.2 eV
of light] 58. As electron moves away from nucleus its K.E. –
[1] c/1.37 [2] c/1370 [3] c/13.7 [4] c/137 [1] Decreases [2] Increases
48. Which of the following curves may represent the speed [3] Remains constant [4] None
of the electron in a hydrogen atom as a function of the st
59. Energy required to pull out an electron from 1 orbit
principal quantum number n –
of hydrogen atom to infinity is 100 units.The amount
nd
of energy needed to pull out the electron from 2 orbit
to infinity is –
[1] 50 units [2] 100 units [3] 25 units [4] Zero
60. The radii of two of the first four Bohr orbits of the
hydrogen atom are in the ratio 1 : 4. The energy
[1] a [2] b [3] c [4] d
difference between them may be –
49. When an electron of charge e and mass m moves with
[1] Either 12.09 eV or 3.4 eV
velocity v about the nuclear charge Ze in the circular
orbit of radius r, the potential energy of the electron [2] Either 2.55 eV or 10.2 eV
is given by - [3] Either 13.6 eV or 3.4 eV
2 2 2 2 2
[1] Ze /r [2] –Ze /r [3] Ze /r [4] mv /r [4] Either 3.4 eV or 0.85 eV
50. The ionization energy of H atom is 13.6 eV what will 61. Which is correct for any kind of species –
+ +2
be ionization energy of He and Li ions- [1] (E2 – E1) > (E3 – E2) > (E4 – E3)
[1] - 54.4 eV and - 12.2 eV [2] (E2 – E1) < (E3 – E2) < (E4 – E3)
[2] 122.4 eV and 55.4 eV [3] (E2 – E1) = (E3 – E2) = (E4 – E3)
[3] 54.4 eV and 122.4 eV [4] (E2 – E1) = 1/4 (E3 – E2) = 1/9(E4 – E3)
st nd
[4] 12.1 eV and 13.6 eV 62. The ratio of difference between 1 and 2 Bohr's orbits
nd rd
51. The value of : [2p(energy)–1s(energy)] for H–atom energy to that between 2 and 3 orbits energy is –
would be – [1] 1/2 [2] 1/3 [3] 27/5 [4] 5/27
[1] 10.2 eV [2] 13.6 eV 63. If the energy of an electron in hydrogen atom is given
–1
[3] 3.4 eV [4] None of these by expression, –1312/n² kJ mol , then the energy
required to excite the electron from ground state to
52. The separation energy of the electron present in the
second orbit is
shell n = 3 is 1.51 eV. What is the energy in the first
excited state – [1] 328 kJ/mol [2] 656 kJ/mol
[3] 984 kJ/mol [4] 1312 kJ/mol
[1] –1.51 eV [2] –3.4 eV
64. The potential energy of the electron present in the
[3] +1.51 eV [4] +3.4 eV 2+
ground state of Li ion is represent by –
53. When an electron jump from L to K shell -
3e 2 3e 3e 2
[1] Energy is absorbed [2] Energy is released [1]  [2] – 4 r [3] – [4] None
40r 0 4 0r
[3] Energy is neither absorbed nor released
65. The ionization energy of hydrogen atom (in the ground
[4] Energy is sometimes absorbed and sometimes state) is x kJ. The energy required for an electron to
released nd rd
jump from 2 orbit to the 3 orbit will be –
+3
54. The ratio of ionization energy of H and Be is - [1] x/6 [2] 5x [3] 7.2 x [4] 5x/36
th rd
[1] 1 : 1 [2] 1 : 3 [3] 1 : 9 [4] 1 : 16 66. In H–atom electron jumps from 4 to 3 energy level,
55. The energy of the electron at infinite distance from the the energy released is –
–19 –19
nucleus in Bohr’s model is taken as - [1] 1.06 × 10 J/atom [2] 3.03 × 10 J/atom
–12 –19
[1] Zero [2] Positive [3] Negative [4] Any value [3] 1.06 × 10 J/atom [4] 2.12 × 10 J/atom
 –
67. The graphical representation of energy of e and atomic 79. Suggest two transitions in the atomic spectrum
number is – hydrogen for which the wave number ratio is 108 : 7
[1] First Lyman and first Bracket series transition
[2] First and second Lyman series transition
[1] [2]
[3] First Lyman and first Balmer series transition
[4] First Lyman and first Paschen series transition
80. If n = x – 2, then the last value of  is –
[3] [4] [1] n + 1 [2] x – 1 [3] x – 3 [4] 1 & 3 both
81. De Brogli's equation is -
68. Supposing the I.P. of hydrogen atom is 960 eV. Find
out the value of principal quantum number having the [1] n  = 2d sin [2] E = h
energy equal to – 60 eV – 2 h
[3] E = mc [4]  = mv
[1] n = 2 [2] n = 3 [3] n = 4 [4] n = 5
69. Maximum wave length is of - 82. The wavelength associated with a golf ball weight
200 g and moving with a speed of 5 m/hr is of the order
[1] X - ray [2] Infra Red
of –
[3] Blue light [4] Ultra violet –10 –20 –30 –40
[1] 10 m [2] 10 m [3] 10 m [4] 10 m
70. In U.V. region, the spectrum line is obtained when
83. A helium moleule is moving with a velocity of
electron jumps from n = 4 to n = ............ 2 –1
2.40 x 10 ms at 300k. The de-Broglie wave length
[1] 1 [2] 2 [3] 3 [4] Zero is about-
71. In the Rydberg equation [for H–atom] What is the value
[1] 0.416 nm [2] 0.83 nm
of n1 if the lines appear in the visible region –
[3] 803 Å [4] 8000 Å
[1] 1 [2] 3 [3] 2 [4] 4
84. Calculate the de-Broglie wave length of the electrone
72. Line spectra is characteristic of -
in the ground state of hydrogen atom , given that its
[1] Atoms [2] Molecules kinetic energy is 13.6 ev- (1ev = 1.602 x 10 J)
– 19

[3] Radicals [4] Ions [1] 3.328 x 10

–10
m [2] 2.338 x 10
–10
m
73. The wave length of third line of lyman series of H– [3] 3.328 x 10
10
m [4] 2.338 x 10 m
9

spectrum will be –
85. Two particles A and B are in motion. If the wavelength
9 16 4 16 –8
associated with the particle A is 5.0×10 m, the
[1] [2] [3] [4]
8R 15R 3R 3R wavelength of particle B having momentum half of A
74. In hydrogen atom, If an electron jumps from n = 6 to is –
–8 –8
n = 2, how many possible spectral lines are obtained– [1] 2.5 × 10 m [2] 1.25 × 10 m
–7 –8
[1] 15 [2] 10 [3] 6 [4] 12 [3] 1.0 × 10 m [4] 1.0 × 10 m
nd th
75 What is difference in wavelength of the 2 and 4 lines 86. If E1 , E2 and E3 represent repectively the kinetic
of Lyman series in spectrum of hydrogen atom – energies of an electron, an alpha particle and a proton
[1] 76Å [2] 190Å [3] 390Å [4] 262 Å each having same de Broglie wavelength then -
76. If each hydrogen atom is excited by giving 8.4 eV of [1] E1 > E3 > E2 [2] E2 > E3 > E1
energy, then the number of spectral lines emitted is [3] E1 > E2 > E3 [4] E1 = E2 = E3
equal to–
87. If the total energy of an electron in a hydrogen like
[1] None [2] Two [3] Three [4] Four atom in excited state is –3.4 eV, then the de Broglie
77. If the shortest wavelength of H atom in Lyman series wavelength of the electron is –
+
is x, then longest wavelength in – Balmer series of He [1] 6.6 × 10
–10
m [2] 3 × 10
–10
m
is – 9 –12
[3] 5 × 10 m [4] 9.3 × 10 m
9x 36 x x 5x 88. A particle A moving with a certain velocity has a de
[1] [2] [3] [4]
5 5 4 9 Broglie wavelength of 1 Å. If particle B has mass 25%
78. An atom has x energy level then total number of lines of that A and velocity 75% of that of A, the de Broglie
in its spectrum are – wavelength of B will be approximately –
[1] 1 + 2 + 3 ............... (x + 1) [1] 1Å [2] 5.3 Å [3] 3Å [4] 0.2Å
2
[2] 1 + 2 + 3 ........... (x ) 89. In H–atom, if x is the radius of first Bohr orbit,
rd
[3] 1 + 2 + 3 .......... (x – 1) de–Broglie wavelength of an electron in 3 orbit is -
[4] (x + 1)(x + 2)(x + 4) [1] 3x [2] 6x [3] 9x/2 [4] x/2
90. If uncertainty in position of electron is zero, the 103. Which orbital has two angular nodes –
uncertainty in its momentum would be – [1] s [2] p [3] d [4] f
[1] Zero [2] h/2 [3] 3h/2 [4] Infinity 104. The correct set of n, , m, quantum numbers for the
91. W hich orbital is represented by the complete unpaired electron of chlorine atom is
wavefunction 320. [1] 2, 1, 0 [2] 2, 1, 1 [3] 3, 1, 1, [4] 3, 0 , 0
[1] 3d [2] 4d [3] 4p [4] 4s 105. If the value of (n + ) is more than 3 and less than 6,
92. There is no difference between a 2p and 3p orbitals what will be the possible number of orbitals –
regarding –
[1] 9 [2] 10 [3] 6 [4] 13
[1] Shape [2] Size [3] Energy [4] Value of n th
106. The set of quantum numbers for the 19 electron in
93. Which of the following sets of quantum number chromium is -
correctly describe an electron in an atom -
[1] n = 4 ,  = 0 , m = 0 , s = + ½ or – ½
n  m s
[2] n = 3 ,  = 2 , m = 1, s = +½ or – ½
[1] 4 4 3 +½
[3] n = 3 ,  = 2 , m = –1 , s = +½ or –½
[2] 3 2 –3 -½
[4] n = 4 ,  = 1 , m = 0 , s = +½ or –½
[3] 0 0 0 +½
107. The total number of electron in Gold which is having
[4] 3 1 0 –½ =2-
94. A given orbital is labeled by the magnetic quantum
[1] 10 [2] 20 [3] 30 [4] 79
number m = –1. This could not be -
108. The value of n,  and m for the last electron in Arsenic-
[1] s - orbital [2] p-orbital
[1] 4, 1, 0 [2] 3, 2, +1 [3] 3, 2, –1 [4] 4, 2, +1
[3] d-orbital [4] f-orbital
109. Which set of quantum numbers is possible for the last
95. A d-subshell in an atom in the presence of magnetic +
electron of Mg ion -
field is -
[1] n = 3 ,  = 2 , m = 0 , s = +1/2
[1] Five fold degenerate [2] Seven fold degenerate
[2] n = 2 ,  = 3 , m = 0 , s = +1/2
[3] Three fold degenerate [4] None degenerate
96. The magnetic quantum number of an atom is related [3] n = 1 ,  = 0 , m = 0 , s = +1/2
to the - [4] n = 3 ,  = 0 , m = 0 , s = +1/2
[1] Size of orbit 110. 4s and 3p electrons can have identical values of these
[2] Spin angular momentum two quantum numbers –

[3] Orbital angular momentum [1] n and  [2]  and m [3] m and s [4] n and s
[4] Orientation of the orbital 111. The orbital angular momentum of an electron in 2p-
orbital is -
97. The number of nodal plane & nodal surface for 1s-
[1] 1 & 1 [2] 1 & 2 [3] 0 & 1 [4] 0 & 0 h h h
[1] [2] Zero [3] [4]
98. The quantum no. that determines the shape of the 4 2 2
orbital is ..... quantum no. - 112. A subshell with  = 2 can take up -
[1] Principal [2] Azimuthal [1] 10 electrons [2] 14 electrons
[3] Magnetic [4] Spin [3] 2 electrons [4] 6 electrons
99. The maximum number of electrons in 'N' shell is - 113. For n = 3, which value of  is not possible -
[1] 18 [2] 32 [3] 2 [4] 8 [1] 0 [2] 3 [3] 1 [4] 2
100. For n = 3,  = 1 the corresponding orbitals are - 114. How many sets of quantum number are possible for
–2
[1] s, p x , p y [2] s, p z , p y the electron present in He anion -
[3] s , p x , d xy [4] px , py, pz [1] 2 [2] 5 [3] 4 [4] 7
101. The number of nodal planes is greatest for the orbital- 115. The number of radial nodes and the value of orbital
th
[1] 1 s [2] 2 p [3] 3 d [4] 3 p angular momentum of the 28 electrons added in
Ni(28) atom are respectively –
102. Correct set of four quantum numbers for valence elec-
trons of rubidium (Rb = 37) is - [1] 1 & 2 h/2 [2] 2 & 6 h/2
[1] 5, 0 , 0, +1/2 [2] 5, 1, 0, +1/2
[3] 5, 1, 1, +1/2 [4] 6, 0, 0 +1/2 [3] Zero & 6 h/2 [4] Zero & 2 h/2
116. An atom has 2 electron in K shell, 8 electrons in L 131. The number of electrons shared by each atom of
shell, and 6 electron in M shell. The number of nitrogen in nitrogen molecule is -
s - electrons present in that element is - [1] 2 [2] 6 [3] 3 [4] 4
[1] 6 [2] 5 [3] 7 [4] 10 132. Which of the following represents an alkaline earth
117. Number of electron in the outermost orbit of the metal -
element of atomic number 15 is - 2 1 2 2 6
[1] 1s , 2s [2] 1s , 2s 2p
[1] 1 [2] 3 [3] 5 [4] 7 2 2 6 2 2 2 6 2 2
[3] 1s , 2s 2p , 3s [4] 1s , 2s 2p , 3s 3p
118. Which of the following pair having same number of
133. An electron will have the highest energy in the set-
orbitals -
[a] N , O [b] O, F [c] Na, K [d] S, Cl [1] 3, 2, 1, 1/2 [2] 4, 2 , -1 , 1/2

The correct answer is - [3] 4, 1 , 0, -1/2 [4] 5, 0 , 0, 1/2

[1] a, b, c [2] b, c, d [3] c, d, a [4] a, b, d 134. The maximum number of 3d-electrons having spin
quantum number s = +1/2 are -
119. The total number of shell, subshell and orbitals are
+2
used in Fe - [1] 10 [2] 14 [3] 5 [4] None
[1] 4, 7,14 [2] 3, 6,14 [3] 4, 6,14 [4] 3, 7,4 135. Electronic configuration of niobium (Nb = 41) is :-
5 4 1 6
120. A transition element X has configuration [Ar]d in its [1] [Kr] 4d , 5s [2] [Kr] 4d
+3 oxidation state. Its atomic number is – [3] [Kr] 4d , 5s
3 2
[4] [Kr] 5s 5p
2 3

[1] 22 [2] 25 [3] 26 [4] 19 136. The group not showing similarity in unpaired electrons
121. In which (n + ) rules not applicable - is –
[1] Cu, Cr [2] Cu, Zn [3] Ag, Zn [4] All of these 3 7 4 10 7 3 4 8
[1] d , d [2] f , f [3] d , p [4] d , d
122. Krypton (36Kr) has the eletronic configuration (18Ar) 137. The number of s-electrons in Mg atom is -
2 10 6 th
4s 3d 4p . The 37 electron will go into which of
[1] 4 [2] 2 [3] 6 [4] 8
the following sub levels -
138. In a quantum level the energies of the orbitals will be
[1] 4f [2] 4d [3] 3p [4] 5s
in the order -
123. Hund's rule is applicable for -
[1] s = p > d > f [2] s > p > d > f
[1] 3px, 3py, 3pz [2] 3s , 3p, 3d
[3] s < p < d < f [4] None of these
[3] 6s, 5p, 4d [4] All of these
139. For the energy levels in an atom which one of the
124. The number of valence electrons in carbon atom are-
following statements is/are correct –
[1] 0 [2] 2 [3] 4 [4] 6
[1] The second principal energy level can have 4
125. Which of the following pair has identical configuration-
+ + –
sub-energy levels and contain a maximum of 8
[1] Li and He [2] Cl and Ar electrons.
+
[3] Na and K [4] F and Ne [2] The M energy level can have a maximum of 32
–
126. Electronic configuration of H is - electrons
0 1 2 1 1
[1] 1s [2] 1s [3] 1s [4] 1s , 2s [3] The 4s sub-energy level is at a lower energy than
127. Which of the following has minimum number of un- the 3d sub-energy level.
paired d-electrons ? [4] None of them
3+ 2+ 2+ 3+
[1] Fe [2] Mn [3] Co [4] Co 140. Order of no. of revolution/sec 1, 2, 3, 4 for I, II, III
2+
128. How many unpaired electron are present in Ni - and IV orbits is –
[1] 0 [2] 2 [3] 4 [4] 8 [1]  1 >  2 >  3 >  4 [2]  4 >  3 >  2 >  1
129. Cations with pseudo inert gas configuration is - [3]  1 >  2 >  4 >  3 [4]  2 >  3 >  4 >  1
+ +2 + +2
[1] Cu , Zn [2] Ag , Cd 141. If elements with principal quantum number n > 4 is
+ +2
[3] Au , Hg [4] All of these not found in nature, the number of possible elements
130. Angular momentum of an electron in an orbital is given would be–
by - [1] 60 [2] 32 [3] 64 [4] 50
h h 142. The difference in angular momentum associated with
[1] n [2] × (  1) the electron in two successive orbits of hydrogen atom
4 2
is –
h
[3] n [4] None of these [1] h/ [2] h/2 [3] h/2 [4] (n – 1) h/2
2
143. A certain element has the quantum number n = 2, 153. Energy levels A, B, C of a certain atom corresponds
 = 1, m = 0, s = +½ for its highest energy electron. to increasing values of energy, i.e., EA < EB < EC. If
This element could be – 1, 2 and 3 are the wavelengths of radiations cor-
responding to the transitions C to B, B to A and C to
[1] Halogen [2] An alkaline earth metal
A respectively, which of the following statement is
[3] An alkali metal [4] A transition metal correct –

144. Ratio of time period of electron in first and second orbit

of H atom would be –

[1] 1 : 18 [2] 1 : 8 [3] 1 : 2 [4] 2 : 1

145. Dimensions of Planck’s constant are - 1 2

[1] 3 = 1 + 2 [2] 3 =
[1] force × time [2] energy × distance 1   2
 2 2
[3] energy / time [4] energy × time [3] 1 + 2 + 3 = 0 [4]  3 = 1 + 2
a+
146. Which element possess non-spherical orbitals - 154. An ion Mn has the magnetic moment equal to 4.9
B.M. What is the value of a –
[1] He [2] B [3] Be [4] Li
[1] 3 [2] 4 [3] 2 [4] 5
147. Energy will be absorbed in separating - 155. How many moles of electrons weight one kilogram ?
–31
[1] An electron from a proton (Mass of electron = 9.108 × 10 kg, Avogadro
23
number = 6.023 × 10 ) –
[2] An electron from an electron
23 1 31
[3] An neutron from neutron [1] 6.023 × 10 [2] × 10
9.108
[4] A proton from a proton 6.023 54 1 8
[3] ×10 [4] 9.108  6.023 ×10
9.108
148. Consider the following pairs of ions –
156. Out of first 100 elements, number of elements having
3+ 4+ 2+ 2+
(a) Sc and Ti (b) Mn and Fe electrons in 3d-orbitals are -
2+ 3+ + 2+
(c) Fe and Co (d) Cu and Zn [1] 80 [2] 10 [3] 100 [4] 60

Among these pairs of ions, isoelectronic pairs would 157. Which of the following products in a hydrogen atom
include – are independent of the principal quantum number ? In
the symbols have their usual meanings -
[1] b, c and d [2] a, c and d
[1] V.n [2] E.r [3] E.n [4] 1 & 2 both
[3] a, b and d [4] a, b and c +3
158. 13.5 g of Aluminium when changes to Al ion in
149. The core charge on oxygen is equal to – solution, will lose –
23
[1] 18.0 × 10 electrons
[1] +2 [2] –2 [3] –6 [4] +6 23
[2] 6.022 × 10 electrons
150. The number of waves made by a Bohr electron in an 23
[3] 3.01 × 10 electrons
orbit of maximum magnetic quantum number +2 –
23
[4] 9.1×10 electrons
[1] 3 [2] 4 [3] 2 [4] 1
159. An electron in a hydrogen atom in its ground state
151. If uncertainty in position and momentum are equal, absorbs 1.50 times as much energy as the minimum
then uncertainty in velocity is – required for it to escape from the atom. What is the
wavelength of the emitted electron –
h h 1 h
[1] [2] [3] [4] None [1] 4.70Å [2] 4.70 nm [3] 9.4 Å [4] 9.40 nm
 2 2m 
2+
160. The number of d-electrons in Fe (Z = 26) is not equal
152. For an electron in a hydrogen atom, the wave func- to that of the –
tion, is proportional to exp–(r/a0), where a0 is the
Bohr's radius. What is the ratio of the probability of (1) p-electrons in Ne
finding the electron at the nucleus to the probability (2) s-electrons in Mg
of finding it at a0 -
(3) d-electrons in Fe
2 2 –
[1] e [2] e [3] 1/e [4] Zero (4) p-electrons in Cl
161. If n and  are respectively the principal and azimuthal 168. The correct Schrodinger's wave equation for an elec-
quantum numbers, then the expression for the calcu- tron with E as total energy and V as potential energy
lation of the total no. of electrons in any energy level is –
is –
 2  2  2  8 2
(1)    (E  V )   0
n n1 x 2 y 2 z 2 mh 2
(1)  2(2  1) (2)  2(2  1)
0 n1  2   2   2  8m
(2)    2 (E  V )   0
x 2 y 2 z 2 h
n1  n1
(3)  2(2   1) (4)  2(2   1)  2   2   2  8  2m
0  0 (3)    (E  V )   0
x 2 y 2 z 2 h2
162. The number of photons of light having wave number  2   2   2  8m 2
x in 1 J of energy source is (Planck's constant = h, (4)    (E  V )   0
velocity of light = c)
x 2 y 2 z 2 h
169. Transition from n = 4, 5, 6 to n = 3 in hydrogen
x 1 spectrum gives –
(1) hcx (2) hc/x (3) (4)
hc hcx
(1) Lyman series (2) Paschen series
163. For a particle it is found that uncertainty in velocity
–1 (3) Balmer series (4) Pfund series
(in ms ) is reciprocal of the uncertainty in position (in
m). The mass of the particle will have – 170. Splitting of spectral lines when atoms are subjected
to strong electric field is called –
(1) a fixed value (2) a variable value
(1) Zeeman effect (2) Stark effect
(3) a value of not greater than a particular value (3) Decay (4) Disintegration
(4) a value not less than a particular value 171. As the number of orbit increase from the nucleus, the
164. How many electrons in an atom with atomic number difference between the adjacent energy levels –
105 can have (n + ) = 8 (1) Increases (2) Remains constant
(1) 30 (2) 17 (3) Decreases (4) None
172. A quanta will have more energy if –
(3) 15 (4) unpredictable
(1) The wavelength is larger
165. Two electrons A and B in an atom have the following
(2) The frequency is higher
set of quantum numbers,
(3) The amplitude is higher
A : 3, 2, –2, +1/2
(4) The velocity is lower
B : 3, 0, 0, +1/2
173. Three electrons in p-sublevel must have the quantum
Which statement is correct for A and B – number –
(1) A and B have same energy (1) n = 2 (2) m = 0
(3)  = 0 (4) s = –1/2 or +1/2
(2) A has more energy than B +
174. The total number of valency electrons for NH4 is–
(3) B has more energy than A
(1) 9 (2) 8 (3) 6 (4) 11
(4) A and B represents same electron
175. The number vacant d-orbital in completely excited Cl
166. The frequency of first line of Balmer series in hydro- atom is –
gen atom is  0 . The frequency of corresponding line (1) 2 (2) 3 (3) 1 (4) 4
emitted by singly ionised helium atom is – 176. Which transition of electron in the hydrogen atom
emits maximum energy –
(1) 2 0 (2) 4 0 (3)  0 / 2 (4)  0 / 4
(1) 2  1 (2) 1  4 (3) 4  3 (4) 3  2
167. If 1 and  2 are the wavelength of characteristic X-ray 177. Maximum number of electrons which can be accom-
and gamma rays respectively, then the relation be- modated in a g subshell is –
tween them is – (1) 14 (2) 18 (3) 12 (4) 20
178. The ratio of radii of two nuclei with mass numbers 27
(1) 1  1 /  2 (2) 1   2
and 64 is –
(3) 1   2 (4) 1   2 (1) 1/2 (2) 3/4 (3) 3/2 (4) 2/3
179. W hich of the f ollowing has minimum core 180. How many electrons are present in the kernel of
charge – P15 :-
(1) O (2) Na (3) N (4) Mg (1) 10 (2) 5 (3) 3 (4) 2

EXERCISE - 1 ANSWER KEY

Q. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
A. 3 1 2 4 1 4 3 1 3 3 4 3 3 4 1
Q. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
A. 4 3 3 4 4 2 1 4 2 1 2 1 2 2 2
Q. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
A. 1 2 3 2 1 4 3 1 1 2 1 4 3 3 1
Q. 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
A. 4 4 3 2 3 1 2 2 4 1 3 4 1 3 2
Q. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
A. 1 3 3 3 4 1 4 3 2 1 3 1 2 2 1
Q. 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
A. 1 1 3 4 3 4 3 1 1 3 1 1 2 2 4
Q. 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
A. 1 1 4 1 1 4 4 2 2 4 3 1 3 3 4
Q. 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
A. 1 3 1 4 3 4 1 2 3 3 1 3 4 2 3
Q. 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
A. 1 4 1 3 2 3 3 2 4 2 2 3 2 3 1
Q. 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
A. 4 3 3 3 1 1 2 1 2 4 2 1 2 4 1
Q. 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165
A. 3 4 2 1 4 1 4 4 1 4 4 4 1 2 2
Q. 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
A. 2 3 3 2 2 3 2 4 2 1 1 2 2 2 1
1. If the energy of first orbit of hydrogen atom is –1312 9. An element, X has the following isotopic composition;
200
kJ/mole then the value of IP in KJ/mol is- X : 90%
199
(1) + 1312 (2) –1312 X : 8.0%
202
(3) – 675.5 (4) + 675.5 X : 2.0%
2. How many electron filled in the orbital which have The weighted average atomic mass of the naturally
n = 3,  = 2, m = 2 :– occurring element X is closest to -
(1) 2 (2) 10 (3) 14 (4) 6 (1) 201 amu (2) 202 amu
3.
5
Electronic configuration of Cr is 3d 4s not 3d 4s ,
1 4 2 (3) 199 amu (4) 200 amu
it is explain by the following :- 10. The de Broglie wavelength associated with a ball of
(1) Hund's Rule of maximum multiplicity mass 1 kg having kinetic energy 0.5 J is-
–34 –34
(2) Pauli's exclusion principle (1) 6.626 × 10 m (2) 13.20 × 10 m
–34 –34
(3) 10.38 × 10 m (4) 6.626 × 10 Å
(3) Aufbau principle
11. The ratio of the radius of first three Bohr's orbit is-
(4) Uncertainty principle
(1) 1 : 0.5 : 0.5 (2) 1 : 2 : 3
4. Difference of radius of third and second orbit of
(3) 1 : 4 : 9 (4) 1 : 8 : 27
hydrogen atom –
12. The maximum electrons present in p-orbital -
3 2
(1) 5r1 r(2) (3) r1 (4) r1 – –
2 1 3 (1) 4e (2) with parallel spin 2e
5. For 2px, 2py and 2pz which quantum number same – –
(3) 6e (4) With antiparallel spin 2e
are –
13. W hich is discovered by Rutherfords -partical
(1) n (2) n,  (3) n, , m (4) n, , s experiment -
6. According to Neils Bohr order of energy of 3s, 3p and (1) Nucleus (2) Electron
3d orbital is –
(3) Proton (4) Neutron
(1) 3s > 3p > 3d (2) 3s < 3p < 3d
14. The ratio of mass of the proton and electron is (approx)-
(3) 3s < 3p > 3d (4) 3s = 3p = 3d
3
(1) infinit (2) 1.8 × 10
7. In which the following pairs, the two species are
iso-structural - (3) 1 : 8 (4) None of these

(1) SO 32 and NO3

–
(2) BF3 and NF3 15. Which of the following is the pair of isoelectronic -

–
(3) BrO3 and XeO3 (4) SF4 and XeF4 +3 +3 +3 +2
(1) Sc , Ti (2) Fe , Mn
8. Consider the following sets of quantum numbers - +3
(3) Co , Sr
+3 +3
(4) Fe , Co
+3

n  m s 16. The orientation of an atomic orbital is governed by –

(a) 3 0 0 +½ [1] Principal quantum number
(b) 2 2 1 +½ [2] Azimuthal quantum number
(c) 4 3 –2 –½ [3] Spin quantum number
[4] Magnetic quantum number
(d) 1 0 –1 –½
–31
17. Given : The mass of electron is 9.11 × 10 kg Planck
(e) 3 2 3 +½ –34
constant is 6.626 × 10 Js, the uncertainty involved
Which of the following sets of quantum number is not in the measurement of velocity within a distance of 0.1
possible - Å is –
(1) a, b, c and d (2) b, d and e [1] 5.79 × 10 ms
5 –1
[2] 5.79 × 10 ms
6 –1

7 –1 8 –1
(3) a and c (4) b, c and d [3] 5.79 × 10 ms [4] 5.79 × 10 ms
18. The most probable radius (in pm) for finding the electron 28. Which of the following sets of quantum numbers is
+
in He is - correct for an electron in 4f orbital ?
(1) 0.0 (2) 52.9 (3) 26.5 (4) 105.8 1
[1] n = 4,  = 3, m = +4, s = +
19. The isoelectronic pair is - 2
– –
(1) Cl2O,ICl2 (2) ICl2 , ClO2 1
+ – – + [2] n = 4,  = 4, m = –4, s = –
(3) IF2 , I3 (4) CIO2 , CIF2 2
20. Number of electrons in carbon atom is- 1
[3] n = 4,  = 3, m = +1, s = +
[1] 4 [2] 6 [3] 8 [4] 10 2
21. Which of the following are found in the nucleus – 1
[4] n = 3,  = 2, m = –2, s = +
2
[1] e, p [2] p, n [3] e, n [4] None 29. Consider the ground state of Cr atom (Z = 24). The
22. Electronic configuration of Nitrogen is – numbers of electrons with the azimuthal quantum
1 1 1 numbers,  = 1 and 2 are, respectively:–
[1] 1s², 2s², 2px , 2py 2pz
2 2 3
[1] 12 and 4 [2] 12 and 5
[2] 1s , 2s , 2px
[3] 16 and 4 [4] 16 and 5
2 2 2 1
[3] 1s , 2s , 2px , 2py 30. The wavelength of the radiation emitted, when in a
2 2 2 1
[4] 1s , 2s , 2px , 2py hydrogen atom electron falls from infinity to stationary
7
23. Atomic number implies – state 1, would be (Rydberg constant = 1.097 × 10
–1
m ) :–
[1] Number of protons
[1] 91 nm [2] 192 nm
[2] Number of neutrons [3] 406 nm [4] 9.1 × 10
–8
nm
[3] Atomic mass 31. The frequency of radiation emitted when the electron
[4] Valency falls from n = 4 to n = 1 in a hydrogen atom will be
–18 –1
(Given ionization energy of H = 2.18 × 10 J atom
24. Principal quantum number denotes – –34
and h = 6.625 × 10 Js)
[1] Size of atom 15 –1 15 –1
[1] 1.54 × 10 s [2] 1.30 × 10 s
[2] Spin angular momentum 15 –1 15 –1
[3] 3.08 × 10 s [4] 2.00 × 10 s
[3] Orbital angular momentum 32. Zeeman effect explain by the spliting of line in the ....
[4] Orientation of orbital
[1] Magnetic field [2] Electric field
25. Bohr model explains –
[3] 1 and 2 [4] None of these
[1] Spectrum of Hydrogen atom only
33. If Azimuthal quantum number () = 2, then calculate
[2] Spectrum of single electron species minimum principle quantum number (n)-
[3] Spectrum of Hydrogen molecule [1] 1 [2] 2 [3] 3 [4] 4
[4] Energy spectrum 34. Which of the following element outermost orbit's last
electron has magnetic quantum number m = 0 ?
26. The size of nucleus is measured in –

[1] Na [2] O [3] Cl [4] N

[1] cm [2] A° [3] Fermi [4] a.m.u.
35. Rutherfords -particle dispersion experiment
27. The energy of second Bohr orbit of the hydrogen atom concludes –
is – 328 kJ mol–1 ; hence the energy of fourth Bohr orbit [1] All positive ions are deposited at small part.
would be – [2] All nagative ions are deposited at small part.
[1] – 41 kJ mol –1
[2] – 82 kJ mol –1
[3] Protons moves around the electrons.
[3] – 164 kJ mol–1 [4] – 1312 kJ mol–1 [4] Neutrons are charged particles.
36. In the bohr's orbit, what is the ratio of total kinetic 48. Which is not electromagnetic radiation-
energy and total energy of electron– [1] Infrared rays [2] X-ray
[1] –1 [2] –2 [3] 1 [4] +2
[3] Cathode rays [4] Gamma rays
37. Which orbital is impossible –
49. Correct order of size is –
[1] 2p [2] 3f [3] 5s [4] 4d + – – +
2 2 6 2 3
[1] I > I > I [2] I > I > I
38. Electronic configuration 1s 2s 2p 3s 3p element – + + –
[3] I > I > I [4] I > I > I
belongs to which group of periodic table –
50. The basis of three unpaired electrons in the
[1] 3 [2] 11 [3] 5 [4] 15 configuration of nitrogen is –

39. Which is isoelectronic with sulphide ion – [1] Auf-bau principle

[2] Pauli's principle
[1] Cl [2] Ne [3] Ar [4] Kr [3] Hund's principle
40. Quantum number n = 3,  = 2, m = +2 shows how [4] Uncertainty principle
many orbitals –
51. Outer electronic configuration of the element of atomic
[1] 1 [2] 2 [3] 3 [4] 4
number 24 is-
41. Sub-shell designated by azimuthal quantum number 2 6 5 1 2 6 4 2
[1] 3s 3p 3d 4s [2] 3s 3p 3d 4s
 = 3 can have maximum number of electrons-
2 6 6
[3] 3s 2p 3d [4] None
52. Which set of quantum numbers for an electron of an
[1] 14 [2] 6 [3] 10 [4] 0
atom is not possible –
42. Which sub-shell is not permissible-
[1] 2d [2] 4f [3] 6p [4] 3s 1
[1] n = 1,  = 0, m = 0, s = +
2
43. The minimum real charge on any particle which can
exist is- 1
–19 [2] n = 1,  = 1, m = 1, s = +
[1] 1.6 × 10 coulomb 2
–10
[2] 1.6 × 10 coulomb 1
–10 [3] n = 1,  = 0, m = 0, s = –
[3] 4.8 × 10 coulomb 2
[4] Zero
1
44. Electron enters the sub-shell for which (n + ) value is [4] n = 2,  = 1, m = –1, s = +
2
minimum. This is enunciated as-
53. A metal in its di positive state has the electronic
[1] Hund's rule configuration 2, 8, 14 and has the atomic weight equal
[2] Aufbau principle to 56. Number of neutrons in its nucleus would be –
[3] Heisenberg uncertainty principle
[4] Pauli's exclusion principle [1] 30 [2] 32 [3] 34 [4] 28
45. Smallest cation is- 54. Which quantum number will determine the shape of the
[1] Na
+
[2] Mg
2+
[3] Ca
2+
[4] Al
3+ orbital -

46. The mass of a neutron is of the order of- [1] Principal quantum number

[1] 10
–23
Kg [2] 10
–24
Kg [2] Azimuthal quantum number
–26 –27 [3] Magnetic quantum number
[3] 10 Kg [4] 10 Kg
47. Which of the following pair of orbitals possess two [4] Spin quantum number
nodal planes- 55. Which of the following are isoelectronic species
+ – +
[1] pxy, d x 2 – y 2 [2] dxy, dzx I – CH 3, II – NH2 , III – NH 4, IV – NH3

[3] pyz, dzx [4] dz2 , d x 2 – y 2 [1] I, II, III [2] II, III, IV [3] I, II, IV [4] I and II
 th
56. Which of the following set of quantum numbers belong 63. The energy of an electron in n orbit of hydrogen atom
to highest energy- is-

1 – 13.6 – 13.6
[1] n = 4,  = 0, m = 0, s = + [1]
n4
eV [2]
n3
eV
2
1 – 13.6 – 13.6
[2] n = 3,  = 0, m = 0, s = + [3]
n2
eV [4] eV
2 n
64. Which is correct statement about proton-
1
[3] n = 3,  = 1, m = 1, s = + [1] Proton is nucleus of deuterium
2
[2] Proton is ionized hydrogen molecule
1
[4] n = 3,  = 2, m = 1, s = + [3] Proton is ionized hydrogen atom
2
57. The de-Broglie wavelength of a particle with mass 1 g [4] Proton is -particle
and velocity 100 m/s is- 65. Heaviest particle is-
–33 –34
[1] 6.63 × 10 m [2] 6.63 × 10 m [1] Meson [2] Neutron
–35 –36 [3] Proton [4] Electron
[3] 6.63 × 10 m [4] 6.65 × 10 m
58. The uncertainty in momentum of an electron is 66. The four quantum number for the valence shell electron
–5
1×10 kg–m/s. The uncertainty in its position will be- or last electron of sodium (Z = 11) is-
–34 2
(h = 6.62 × 10 kg–m /s)- [1] n = 2,  = 1, m = –1, s = –1/2
[1] 1.05 × 10
–28
m [2] 1.05 × 10
–26
m [2] n = 3,  = 0, m = 0, s = +1/2
[3] 5.27 × 10
–30
m [4] 5.25 × 10
–28
m [3] n = 3,  = 2, m = –2, s = –1/2

59. Which of the following has more unpaired d-electrons- [4] n = 3,  = 2, m = 2, s = +1/2
rd nd
67. The ratio of radii of 3 and 2 Bohr's orbit of hydrogen
[1] Zn
+
[2] Fe
2+
[3] Ni
3+
[4] Cu
+ atom is-

60. Ground state electronic configuration of nitrogen atom [1] 3 : 2 [2] 4 : 9 [3] 9 : 4 [4] 9 : 1
can be represented by- 68. Which of the following configuration follows the Hund's
rule-
[1] [2]
2s 2p 2s 2p

[3] [4] None of these [1] [He] [2] [He]

61. The electrons identified by quantum numbers n and  2s 2p 2s 2p

(i) n = 4,  = 1 (ii) n = 4,  = 0 [3] [He] [4] [He]
(iii) n = 3,  = 2 (iv) n = 3,  = 1
69. W hich triad of quantum number [n, , m] is not
can be placed in order of increasing energy from the applicable to 3d-electron-
lowest to highest, as-
[1] 3, 2, 0 [2] 3, 1, –1 [3] 3, 2, –2 [4] 3, 2, +1
[1] (iv) < (ii) < (iii) < (i) [2] (ii) < (iv) < (i) < (iii)
70. The atomic size is nearly-
[3] (i) < (iii) < (ii) < (iv) [4] (iii) < (i) < (iv) < (ii) –10 –6 –7 –12
[1] 10 m [2] 10 m [3] 10 m [4] 10 m
–11 –34
62. If wavelength of photon is 2.2×10 m, h = 6.6×10 6
71. [Ar] 3d is the configuration of the following ion-
Js, then momentum of photon is-
–23 –1
[1] 3 × 10 kg ms [1] Fe
+2 +3
[2] Ti [3] Co
+2
[4] Cr
+3

22 –1
[2] 3.33 × 10 kg ms 72. Number of orbitals having paired electrons for gaseous
–44 –1
[3] 1.452 × 10 kg ms Fe are-
43 –1
[4] 6.89 × 10 kg ms [1] 4 [2] 11 [3] 15 [4] 19
73. Which of the following explain the sequence of filling 83. Number of protons, neutrons and electrons in the
231
the electrons in different orbitals- element 89y is-

[1] Hunds' rule [2] Octet rule [1] 89, 231, 89 [2] 89, 89, 242

[3] Aufbau principle [4] All of these [3] 89, 142, 89 [4] 89, 71, 89

74. The Bohr orbit radius for the hydrogen atom (n = 1) is 84. If electron falls from n = 3 to n = 2, then emitted energy
approximately 0.530 A. The radius for the first excited is-
state (n = 2) orbit is-
[1] 10.2 eV [2] 12.09 eV
[1] 0.13 Å [2] 1.06 Å [3] 4.77 Å [4] 2.12 Å
[3] 1.9 eV [4] 0.65 eV
75. The position of both an electron and a helium atom is
85. The electronic configuration of gadolinium (atomic no.
known within 1.0 nm and the momentum of the
–26 –1 64) is-
electron is known within 50 × 10 kg ms . The
8 9 2 7 1 2
minimum uncertainty in the measurement of the [1] [Xe] 4f 5d 6s [2] [Xe] 4f 5d 6s
momentum of the helium atom is- 3
[3] [Xe] 4f 5d 6s
5 2
[4] [Xe] 4f 5d 6s
6 2 2

–1 –1
[1] 50 kg ms [2] 60 kg ms 86. The configuration 1s 2s 2p 3s shows-
2 2 5 1

–26 –1 –26 –1
[3] 80 × 10 kg ms [4] 50 × 10 kg ms [1] Ground state of fluorine atom.
+
76. The energy of the electron in the first orbit of He is [2] Excited state of fluorine atom.
–20
– 871.6 × 10 J. The energy of the electron in the
[3] Excited state of neon atom.
first orbit of hydrogen would be–
–
–20 –20 [4] Excited state of ion O 2.
[1] – 871.6 × 10 J [2] – 435.8 × 10 J

[3] – 217.9 × 10
–20
J [4] – 108.9 × 10
–20
J 87. If n +  = 6, then total possible number of subshells
would be-
77. The energy of an electron in the first Bohr orbit of H
atom is – 13.6 eV. The possible energy value (s) of the [1] 3 [2] 4 [3] 2 [4] 5
first excited state(s) for electrons in Bohr orbits to 88. In neutral atom, which particles are equivalent-
hydrogen is (are)-
+ + – + – + + 0
[1] –3.4 eV [2] –4.2 eV [3] –6.8 eV [4] +6.8 eV [1] p , e [2] e , e [3] e , p [4] p , n
78. Which of the following species not contains neutrons 89. In an element going away from nucleus, the energy of
particle-
+2
[1] H [2] Li [3] C [4] O [1] Decreases [2] Not changing
40 40 40
79. 18Ar , 19K , 20Ca is – [3] Increases [4] None of these
[1] Isotopes [2] Isobars 90. Five valence electrons of 15 P are labelled as
[3] Isotonic [4] Isodiapheres If the spin quantum of B and Z is
80. Discover of positron by –
+ 1/2, the group of electrons with three of the quantum
[1] Paulling [2] Anderson [3] Yukawa [4] Segare
number same are-
81. Electronic configuration of more electronegative
[1] AB, XYZ, BY [2] AB
element is –
2 3 2 4 2 5 2 6 [3] XYZ, AZ [4] AB, XYZ
[1] ns np [2] ns np [3] ns np [4] ns np

82. In the ground state configuration of Cr24 how many 91. The first use of quantum theory to explain the structure

orbitals are present having paired and unpaired of atom was made by-

electrons & [1] Heisenberg [2] Bohr

[1] 10 [2] 12 [3] 15 [4] 18 [3] Planck [4] Einstein
92. Aufbau principle is not satisfied by- 102. Which statement is not correct for n = 5, m = 3-

[1] Cr and Cl [2] Cu and Ag [1]  = 4

[3] Cr and Mg [4] Cu and Na [2]  = 0 , 1, 2, 3 ; s = + 1/2

[3]  = 3
93. An electron has principal quantum number 3. The
number of its [4] s = +1/2
103. The orbital angular momentum of an electron in 2s
(i) sub-shells and
orbital is-
(ii) orbitals would be respectively
1 h h h
[1] 3 and 5 [2] 3 and 7 [3] 3 and 9 [4] 2 and 5 [1]  . [2] Zero [3] [4] 2 . 2
2 2 2
94. Which electronic level would allow the hydrogen atom
104. For n = 3 energy level, the number of possible orbitals
to absorb a photon but not to emit a photon-
(all kinds) are-
[1] 1 [2] 3 [3] 4 [4] 9
[1] 3s [2] 2p [3] 2s [4] 1s
105. Zeeman effect refers to the-
95. The total number of orbitals in an energy level
[1] Splitting up of the lines in an emission spectrum in
designated by principal quantum number n, is equal to-
a magnetic field.
[2] Splitting up of the lines in an emission spectrum in
2 2
[1] 2n [2] 2n [3] n [4] n the presence of an external electrostatic field.
96. CO has sam e electrons as or the ion that is [3] Emission of electrons from metals when light falls
isoelectronic with CO is- upon them.
+ – + –
[1] N2 [2] CN [3] O2 [4] O [4] Random scattering of light by colloidal particles.
2

97. The maximum probability of finding an electron in the 106. A 3p orbital has-
dxy orbital is- [1] Two spherical nodes
[1] Along the x-axis [2] Two non-spherical nodes

[2] Along the y-axis [3] One spherical and one non-spherical nodes

[3] At an angle of 45° from the x and y-axes [4] One spherical and two non-spherical nodes

[4] At an angle of 90° from the x and y-axes 107. The uncertainty in the position of an electron
–28 4
(mass = 9.1×10 g) moving with a velocity of 3.0×10
98. Which of the following metal ions will have maximum
number of unpaired electrons- –1 h
cm s accurate upto 0.001% will be (Use in the
[1] Fe
+2
[2] Co
+2
[3] Ni
+2
[4] Mn
+2 4
–27
uncertainty expression, where h = 6.626 ×10 erg-s)
99. The shape of an orbital is given by the quantum
number- [1] 1.92 cm [2] 7.68 cm

[1] n [2]  [3] m [4] s [3] 5.76 cm [4] 3.84 cm

100. In a Bohr's model of atom when an electron jumps from 108. Chlorine atom differs from chloride ion in the number of-
n = 1 to n = 3, how much energy will be emitted or [1] Proton
absorbed – [2] Neutron
–11 –10
[1] 2.15 × 10 ergs [2] 0.1911 × 10 ergs [3] Electrons
–12 –10
[3] 2.389 × 10 ergs [4] 0.239 × 10 ergs [4] Protons and electrons
2 2 5 2
101. 1 s , 2s 2p 3s shows configuration of- 109. When an electron revolves in a stationary orbit then-
+3
[1] A in ground state [1] It absorbs energy
[2] Ne in excited state [2] It gains kinetic energy
+1
[3] Mg in excited stated [3] It emits radiation
[4] None of these [4] Its energy remains constant
110. The total number of electrons present in all the 113. Pick out the isoelectronic structures from the following
p-orbitals of bromine are- CH3
+
H3O
+
NH3 CH3
–

[1] 5 [2] 18 [3] 17 [4] 35 I II III IV

111. Total number of unpaired electrons in an atom of [1] I and II [2] I and IV
atomic number 29 is- [3] I and III [4] II, III and IV
[1] 1 [2] 3 [3] 4 [4] 2 114. The shape of p-orbital is –
112. Which of the following statements is not correct for an [1] Elliptical
electron that has the quantum numbers n = 4 and m = 2 [2] Spherical
[3] Dumb-bell
1 [4] Complex geometrical
[1] The electron may have the quantum number s = +
2
115 . Which of the following pair has same electronic
[2] The electron may have the quantum number  = 2 configuration-

[3] The electron may have the quantum number  = 3

+
[1] Ca, Ar [2] Mg, Na
–
[4] The electron may have the quantum number  = 0, 1, 2, 3 [3] Ag, Sn [4] Ar, Cl

ANSWER KEY ATOMIC STRUCTURE EXERCISE-2

Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ans. 1 1 3 1 2 4 3 2 4 1 3 4 1 2 2
Que. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Ans. 4 2 3 4 2 2 1 1 1 2 3 2 3 2 1
Que. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Ans. 3 1 3 1 1 1 2 4 3 1 1 1 1 2 4
Que. 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Ans. 4 2 3 3 3 1 2 1 2 2 4 1 3 2 1
Que. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
Ans. 1 1 3 3 2 2 3 1 2 1 1 2 3 4 4
Que. 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
Ans. 3 1 1 2 2 3 3 3 3 2 3 1 3 3 4
Que. 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
Ans. 2 2 3 4 4 2 3 4 2 2 3 2 2 4 1
Que. 106 107 108 109 110 111 112 113 114 115
Ans. 3 1 3 4 3 1 4 4 3 4