MAIN OBJECTIVE CHEMISTRY IA Atomic Structure

JEE
NCERT BASED QUESTIONs
Stralght Objectlve and Numerical / Integer Type Questions
Statement-II: Cathode ray tube is made of glass containing two thin pieces of metals &sealed in it.
Statement-II: Electrical discharge through the gases takes place only at very low pressure &very
high voltage.
Both Statement-I and Statement-II are correct
b) Both Statement-I and Statement-II are incorrect
Statement-I is correct but Statement-II is incorrect
d Statement-1 is incorrect but Statement-II is correct
The flow of current from cathode to anode was confirmed by making a hole in the and

coating tube behind the anode with phosphorescent material like

a) Cathode, Ag,S b) Cathode, ZnS YAnode, ZnS d) Anode, Ag,S
3
Television set is based on
a) Anode ray tube b Cathode ray tube c) Any discharge tube d) Specific electron tube
Find wrong statement.
a) Cathode rays are visible
b) Cathode rays-behaviour can be observed by using fluorescent (or) phosphorescent materials
c), Nature of cathode rays do not depend on material of electrode and nature of gas taken
d) Cathode rays = electrons
5. J.J. Thomson measured
a) Charge of e b) Mass of e
Ratio of charge to mass of e d) All

6. Find correct option.

a) Specific charge of e =1.7588x10''(clgram)
b) Deflection of e from its original path increases with increase of voltage across the electrode
c) Charge of e =-1.6023 x10-1c
d) Canal rays = (-)vely charged particles flow
7. In Mulliken oil drop experiment the charge of four oil drops is found to be 9.6 x 10-10, 14,4 x 10-10
48x 10-10, 19.2 x 10-10 esu respectively. If the charge of oil drops is due to absorption of electrons
then the charge of electron is
a) 19.2 x 10-10 esu b) 9.6 x 10-10 esu c) 4.8 x 10-10 esu d) 2.4 x 10-10 esu
8. Which is wrong are
a) X-rays are produced when electrons strike the dense metal anode
b) X-rays are not deflected by magnetic and electrical field.
c) X-rays have low penetrating power
d) Roentgen showed that when electrons strike a material in the cathode ray tube, produce rays
which can cause fluorescence

ELITE SERIES for Jr. 1CON Students

 Afomic Structure JEE MAIN
OBJECTIVE
Regarding Rutherfsrnd experiment the xrong option is
a) Rutherford, Geiger and Marsden bombarded a very thin gold foil
5) Thickness of gold foil used a 100nm with CHEMI
a-particles.,
STRY
) Here, cinular fluorescent zinc sulphide sereen is used
d) They ohserved that only a very few a- particles (#T in 2000) bounced
by nearly 18O back. i.e., were
10. The velocity of blue light in vaccum, exactly, is (energy of blue > energy of red deflected
a) 2.9979x10° mse
c) 2.9825x 10°msee-l
b) 3x10'm/sec
d) 2.9865 x 10° m/sec
light)
11. Regarding the graph of black-body radiation the correct one is

A(nm)
I=Intensity of black body radiation (BBR) : 2 = wave lenght of BBR
a) T, =T, b) T,>T,
c) T, <T, d) T, &T, may be equal (or) unequal
12. The energy of one thousand photons of light is
(Joule) if its 2.=3000 A0
a) 3.3125 x10-$J b) 3.3125 x10-6J c) 6.625x10-l8 d) 6.6250 × 10-6J
13. How many of the following does not show photo electric
effect (P.E.E) when a light of 3000A0 falls
on metal target
Metal Li Na K Mg Cu Ag
W, (ev) 2.42 2.3 2.25 3.7 4.8 4.3

a) 2 b) 3 c) 4 d) 5
14. The kinetic energy of ejected electrons is "y" Joul when á radiation of
frequency (y =1.0x 1015 sec-l)
falls on a metal surface (threshold frequency =7 x 10l4 sec-l)
a) 1.988 x10-16J b) 1.672x10-1J
c) 1.672 x10-16J d) 1.988 >x10-1J
15. The radius and energy associated with the 1st orbit of Het ion.
a) r=0.02645nm; E=-8.72 x10-$ J/atom b) r=0.53A"; E =-13.6ev/atom
c) r=106A: E=-27.2 evlatom d) r=2.12A"; E=-2.1x 10 J/atom
16. The Vividh Bharti station of All India Radio, Delhi broadcasts on a frequency of 1368 kHZ.kiloberta)
Calculate the wavelength of the electromagnetic radiations emitted by the transmitter.
c) 219.5 m d) 219.0 m
a) 219.3 m b) 210.2 m
10 teELITE SERIES for Jr. ICON Students
 OBJECTIVE CHEMISTRY IA Atomic Structure
JEE MAIN
What isthe wavelength of light emited when the electron in a hydrogen atom undergoes
transition
17. from an energy level with n 4to an energy level with n 27
a) 496 nm b) 486 nm c) 476 nm d) 489 nm

18. The
limiting line in Balamer series will have a frequency of
a) 3.29x10'-! b) 3.65 x10"s! c) 8.22 x 10s-!
d) 9.22x 1o's!
Calculate the wave number of a photon having an energy equal to 6 electron volts (1 eV 1,602 x
19.
10- J).
a) 4.836 x10cm-! b) 4.363 x10 cm-! c) 4.963 x 10cm-! d) 4.762 x10" cm
20. The kinetic energy of the electron in the nh orbit of an atom is given by the relation
4nme
4
2r'me? 2r'me 41me?
a) b) - c) d)
n'h2 n'h2 n'h?
21. The wavelength of a spectral line for electron transition is inversely related to
a) Z (nuclear charge) b) velocity of electron
c) number of electrons undergoing transition
d) the energy difference between the energy levels involving transition
22. Assertion (A) : Hydrogen has only one electron in its Is orbital but is produces several spectral
lines.
Reason (R) : There are many excited energy level available H atoms.
a) Both (A) and (R) are true and (R) is the correct explanation of (A)
b) Both (A) and (R) are true and (R) is not the correct explanation of (A)
c) (A) is true but (R) is false d) (A)is false but (R) is true
23, The work function of a metal is 4.2 eV, If radiations of 2000 A° fall on the metal then the kinetic
energy of the fastest photo electron is
a) 1.6x1019 b) 16x1010j c) 3.2 x 101J d) 6.4x10-10J
24. Compare the energies of two radiations, one with wavelength of 400 A° and the other with 800 Aº
a) Epo =2Eg00 b) Ez0 = 2E00 c) Ej00= 2Ez) d) Eg00 =2Eso0
25. Calculate the wavelength of radiation emitted when an electron in a hydrogen atom makes a transition
from an energy level with n=3 to a level with n=2
a) 646 m b) 656 m 3) 626 m 4) 676 m
26. Bohr's theory is not apply for
a) Het b) Li+2 c) B e l d) H
27. Bhor's model of atom is not in agreement with
a) Line spectra of hydrogen atom 2) Pauli's principle
c) Planck's theory 4) Heisenberg's principle
28. An electron of mass (m) and charge (-e) moves in circular orbit of radius r around the nucleus of
charge +Ze in unielectron system. In C.G.S system the potential energy of electron is
+Ze? -Ze? Ze
a b c)
2r - r

ELITE SERIES for Jr. 1CON Students 11

 Atomic Structure JEE MAIN
OBJECTIVE
20. If the energy of electron in Hatom is given by expression.
to remove the electron from ground state is
-1312
i mol
n then theCHEMI S
energY
TRY
a) 328 kJ b) 656 kJ c) 984 kJ
d) 1312 kJ
requirea
30. An isotone of ,Ge?' is
A) Ge B) As C) ,Se7
a) A&B only b) B&C only D)Se?
c) B&D only d) B,C&D
31 The energy required to dislodge the electron from
excited isolated H-atom (IE,=13.6eV) 4.
a) = 13.6 eV b) > 13.6 eV c) <13.6 and > 3.4 eV d)
<3.4eV
32. When electronic transition occurs from higher energy state to a
lower energy state with
difference equal to AE the wavelength of line emitted is (approximately)
12397
X10m 12397 12397
energy
a)
AE b) x10" m C x10cm d)
12397
AE AE AE x10" cm
33. In excited H atom, when electron drops from n = 4, 5, 6 to
n= 1, there is emission of
a) U.V. light b) Visible light c) LR. light d) Radio waves
34. If threshold wavelength (h) for ejection of electron from metal is 330 nm, then work
the photoelectric emission is function f
a) 1.2 x 10-18 J b) 1.2 x 10-20 J c) 6 x 10-19 J d) 6 x 1012
35. The first line in the Balmer series in the H atom
will have the frequency
a) 4.57x104s-! b) 3.29 x10$-1 c) 8.22 x 105-! d) 8.05x10!9-1
36. Splitting of spectral lines under the influence of
magnetic field is called
a) Stark effect b) Zeeman effect
c) Photoelectric effect d) Stark
37. The first emission line in the atomic spectrum of
effect&Photoelectric effect
hydrogen in the Balmer series appears at
9R 7R
a) -1 3R 5R
400 b) 144 -cm c) d) -cm
36
38. If wavelength of photon is 2.2 x 10-'m, h = 6.6 x
10-34 Js, then momentum of photon is
a) 3x10 kg ms b) 3.33x 10 kgmsl c) 1452x10 kgms d) 6.89 x
1045 kg ms
39. According to Bohr's theory, the energy required for
the transition of H atom from n=6 to n=8 state is
a) Equal to energy required for the transition from n=5 to
n=7 state
b) Larger than in (1)
c) Less than in (1)
d) Equal to energy for the transition
from n =7to n = 9 state
40. The third line of the Balmer series, in the
emission spectrum of the bydrogen atom, is due t0 the
transition from the
a) fourth Bohr orbit to
the first Bohr orbit b) fifth Bohr orbit to the second Bohr orbit
c) sixth Bohr orbit to
the third Bohr orbit
12 d) seventh Bohr orbit to the third Bohr orbit
ELITE SERIES for Jr. ICON Students
 JEE MAIN OBJECTIVE CHEMISTRY IA
Atomic Structure
41. The force of attraction between nucleus and valency electron in an atom is given by
-kze' kze?
a) F= b) F= d) F=
kze?

The wave number longest spectral line of Balmer series of

H-atom is given by
SRH RH RH
a) v= b) ¼= RH
36 c) V= d) V=.
9 2
A3 The energy related to shortest spectral line of Balmer series of H-atom is given by (x=13.6 evlatom)
X 5x 9x d) AE*
a) b) AE = c) 4E:
36 36 4

A4 The frequency of series limit (last spectral line) of paschan series He* ion
CxRHX4 CxRH×9 CxRH CxRH
a) V=
9
b) V=
4
c) V=
4
d) V=
AS. The second excitation potential of Het ion in (ev/atom) is
a) 40.80 b) 48.36 c) 20.40 d) 24.18

46. The time period of revolution (t) of an electron around the nucleus with radius (r) in an atom is given
by

a) t b) tol e)t
47. The frequency of revolutions (f) made by revolving electron around the nucleus in an atom is given
by
2 n? n
a) fo b) fc d) f«
n' n

48. The wavelength of a ball is x x 10, a body of mass 0.1k.g moving with a velocity of
10m.sec-,Find the value of 'x' ?
49. Calculate the mass of photon with wave length 3.6A0?
1) 6.135 x 10-kg 2) 6.235 >x 10-3°kg 3) 6.6 x 10-kg d) 6.6 x 10"kg
50. What is the total number of orbitals associated with principal quantum number n = 3?
51. Consider 2p, 4s, 5f, 3d arrange these orbitals in the increasing order of their energies?
a) 2p, 5f, 3d, 4s b) 2p, 4s,3d,5f c) 2p, 4s, Sf, 3d d) 5f, 3d, 4s, 2p

52. The possible values of n, Iand mfor 3d orbital

a) n =3, l=2, m =0 b) n=3, I=2, m=-l to +2
c) n = 3, l= 2, m = 2 d) n=3,= 2, m=-2, -1, 0, +1, +2
53. Write the sum of the valence electrons of the following ions H", Nat, O?
54, What is the atomic number of element whose outer most electron represented by ’ 3p ?
S5, Which of the following orbitals are possible?
Ip, 2s, 2p and 3f
ELITE SERIES for Jr. 1CoN Students 13
 OBJECTIVE CHEMISTRY IA S Atomic Structure
JEE MAIN
4). The force of attraction between nucleus and valency clectron in an atom is given by
-kze
b) F=
kze? kze
a) F= c) F d) F=

42. The wave number longest spectral line of Balmer series of H-atom is given by
SRH RH RH RH
a) V=. b) V= c) V= d) V=
36 4 2

A3 The energy related to shortest spectral line of Balmer series of H-atom is given by (x=13.6 evlatom)
X 5x 9x
a) AE= 9 b) AE: c) AE= 4
36 36

AA The frequency of series limit (last spectral line) of paschan series He* ion
CxRHx4 CxRH CxRH
CXRHx9 d) V=
a) V= b) V= c) V= 9
4 4

As The second excitation potential of Het ion in (evlatom) is

a) 40.80 b) 48.36 c) 20.40 d) 24.18

46. The time period of revolution (t) of an electron around the nucleus with radius (r) in an atom is given
by
1
a) t« b) t« o) t d) t«
47. The frequency of revolutions () made by revolving electron around the nucleus in an atom is given
by
n
a) f« nz b) f« z c) f«
n

A8 The wavelength of a ball is x x 103, a body of mass 0.1k.g moving with a velocity of
10m.sec-, Find the value of 'x' ?

49. Calculate the mass of photon with wave length 3.6A0?

1)6.135 x 10kg 2) 6.235 x 10-3°kg 3) 6.6 x 10-5kg d) 6.6 x 10-*kg
50. What is the total number of orbitals associated with principal quantum number n = 3?
51. Consider 2p, 4s, 5f, 3d arrange these orbitals in the increasing order of their energies?
a) 2p, 5f, 3d, 4s b) 2p, 4s,3d,5f c) 2p, 4s, Sf, 3d d) 5f, 3d, 4s, 2p

52. The possible values of n, I and mfor 3d orbital ...

a) n=3,1= 2, m =0 b) n =3, l= 2, m=-l to +2
c)n=3,l=2, m=2 d) n=3, l=2, m= -2, -1, 0, +1, +2
53. Write the sum of the valence electrons of the following ions H', Nat, O-?

54. What is the atomic number of element whose outer most electron represented by ’3p?
55. Which of the following orbitals are possible?
Ip, 2s, 2p and 3f
ELITE SERIES for Jr. ICONStudents 13
|Atomic Structure
JEE
S6. Using s. p. d notation, the incorrect set of MAIN
quantum number. OBJECTIVE
a) n = 1, l= 0 b) n= 3,l= |
57. How many electrons in an atom
may have the
c)n=4,l2 d) n =4, l
4
CHHEMISTRY \A
n=4, m=-/2 following quantum number?
58, If the velocity of electron is 1.6 x 10
ms. Calculate the
electron? de-Broglie wavelength
59. If the velocity of electron in Bohrr's first
orbit is 2.19 x 106 ms.
associated with this
associated with it? Calculate the
60. How many subshells are
associated with n = 4
de-Broglhe wavelength
61. Howmany electrons will be
present in the subshell n = 4, m=-12?
62. A ball of 100g mass is
thrown with a velocity of 100m.s. The wavelength of the de-Broolia ..
associated with the ball is about.
a) 6.63 x 1035 m b) 6.63 x 10-30 m c) 6.63 x 1035 cm d) 6.63 x 10-0
63. The Uncertainty in momentum of moving particle is 1.0 x 10-> kg cm
in its position would be ms.The minimum uncertaintu
a) 5.28 x 10-20 m b) 5.28 x 1049 m c) 6.63 x 1049 m d) 6.63 x 102 m
64. For the electron of the
below
uncertainty in velocity is AV.The uncertainty in itsposition (Ax) is
given
h 27
a) -TUMAv b) h 2um
2 hmAy c) 4amAy d)
hAy
65. The De Broglie wavelength of a 66kg man
sking down Kufri Hill in Simla at 1 x 10 m.sec-! is
a) 1x 1036 m b) 1x 10-37 m c) 1x 108 m d) 1x 10-39 m
66. Magnetic quantum number specifies
a) Size of orbital b) Shape of orbitals
c) Orientation of orbitals in a given space d) Nuclear stability
67. For azimuthal quantum number l= 3, the maximum number of electrons will be
a) 2 b) 6 c) zero d) 14
68. The electrons occupying the same orbital above always spin
a) Paired b) unpaired c) Both a and b d) None the these
69. Which is not permissible subshell?
a) 2d b) 4f c) óp d) 3s
70. The number of waves made by an electron moving in an orbit having maximum magnetic quantum
number +3 is
a) 4 b) 3 c) 5 d) 6
71. Which d-orbital has different shane from rest of all d-orbitals
a) - b) d: e) d,y d) dg
14 ELITE SERIES for Jr. ICON Students
 JEE MAIN OBJECTIVE CHEMISTRY IA Atomic Structure
72. Thetotal number of orbitals in a shell with principal quantum number 'n' is
a) 2n b) 2n c) n? d) n
73. Which orbital is dumb-bell shaped.
a) S b) 2p, c) 3d,: d) 3s
What is the correct orbital designation for the clectron with the quantum number
n4,l=3, m =-2, s = +1/2
a)3s b) 4f c) 5p d) 6s
15 The principal quantum number 'n' can have integral values ranging from?
a) 0 to 10 b) 1 to o. c) 1to (n-1) d) 1to 50

16. The valency orbital configuration of an element with Z = 23 is_

a) 3d5 b) 34°482 c) 3dP48°4p' d) 34°4s²4p
17. TWo electrons in the same orbital may be identified with
a) n b) 1 c) m d) s
78. An improbable configuration
a) [Ar]3d", 4s? b) [Ar]3d', 4s! c) [Ar]3d6, 482 d) [Ar]3d0, 4s!
19. The total number of electrons that can be accommodated in all the orbitals having principal quantum
number 2 and azimuthal quantum number 1 is
a) 2 b) 4 c) 6 d) 8
80. Which atom has as many as s-electrons and p-electrons?
a) H b) Mg c) N d) Na

81. For a d-electrons, the orbital angular momentum is

a) voñ b) /2h c) h d) 2h
82. The correct Schrodinger's wave quantum for an electron with E as total energy and V as potential
energy.

a) + + (E-V)y=0 b) (E-V)y=0
az' mh

c) (E-V)y=0 d -(E-V)å=0
dz?
83. Which has minimum number of unpaired d- electrons?
a) Fet3 b)Co*3 c) CO+2 d) Mnt2
84, A compound of Vanadium has magnetic moment of 1.73 B.M. The electronic configuration of
vanadium ion in the compound is
a) [Ar]34? b) [Ar]3d'4s0 c) [Ar]3d³ d) 3dl04s!
85. Find Wrong statement.
a) Existence of atoms have been proposed by early Indian &Greek philosophers since 400BC
b) Greek atom = a-tomio = uncut - able (non-divisible)
c) Atomic theory was proposed by Greek scientist Dalton called Dalton's Atomic theory (DAT)
d) According to DAT atom" is the ultimate particle of matter
ELITE SERIES for Jr. ICON Students 15
 Atomic Structure JEE MAIN OBJECTIVE CHEMISTRY
IA
86. Find wrong option.
a) Beginning of 20h çentury. it is established that atom can be further divided into
subatomic
b) "DAT" explains law of conservation of mass & Law of constant composition and not particles
Lawof multiple proportions. explains
c) Glass (or) Ebonite, when rubbed with silk (or) fur generate electricity
d) "DAT" not explains the fact in option (c)
87. Find wrong are
a) Proton’ smallest, lightest (+)ve ion obtained from H-gas
b) Neutrons are discovered by Chadwick
c) Neutrons are obtained by bombarding Be-sheet by o -particles (or) B-particles
d) Late discovery of neutron is due to its neutral nature
88. Find incorrect statement.
a) Henry Becquerel observed that radio active elements emit radiations one their own.
b) ,ß,y-radiations belong to electromagnetic radiations.
c) X-rays, Y-rays belong to electromagnetic radiations.
d) Beta rays have ( ve charge with mass equal to e.
89. Find wrong are
a) 0.015% of isotope of hydrogen nucleus has only one neutron.
b) Isotopes show similar chemical behavior and different physical behavior.
c) Atomic weight of ,CI3S (75%) and ,CI" (25%) is 35.5.
d) In railway signals, red light is used rather than blåe light because both differ in their velocity.
90. Which is incorrect option.
a) Diffraction is the bending of wave around an obstacle.
b) Interference is the combination of two waves of the same (or) different frequencies.
c) Frequency range of visible light ranges from 4 x 10!4 Hz to 7.5 x 1014 Hz.
d) Unit of planck's constant = Joul/sec
91. If the wave length of 2nd spectral line of Lyman series is "y" A° then the wave length of 1 spectral
line of Balmer series of Het ion is

a) 3y 3y 8y
d) 5y
b)5 C)
5 5
92. The velocity ratio of revolving e present in Bohr's 3rd orbit of Bet3 jon to 2nd orbit of He ion is
a) 3:4 b) 4:3 c) 2:3 d) 3:2
93. Radius of the fourth orbit in hydrogen atom is 0.85nm.
Calculate the velocity of electron in this orbit
(mass of electron = 9.1 x 10-31 kg)
a) 5.45 x 10 ms
b) 5.56 x 10 ms-l c) 5.86 x 10 ms-! d) 5.89 >x 10 ms-l
94. In unielectron system, the wave
number of any spectral line is directly
a) the number
particles present in the system proportional to
b) the velocity of electron undergoing
1 1 transition
c) n,
d) the charge on the nucleus and the
16
of light used.
ELITE SERIES for Jr. ICON Students
 ocE MAIN OBJECTIVE CHEMISTRY IA Atomic Structure
0s, One among the following statements is correct?

a) An orbital containing an clectron having quantum numbers n = 2: l =0; s= +, isspherical

2
b) The frcquency of X-rays is less than radio wavcs
c) All photons have same energy
d) As intensity of light increases, the
frequency increases.
ok An clectron is excited to fourth energy level in an
atom. It will
Remain there permanently
h) Come back to original state either in one or
more jumps
c) Come back to ground state in one jump
d) Rise to higher energy levels
07. Which experimental observation correctly account for the phenomenon?
Experimental observation Phenomenon
a) X-rays spectra Charge on nucleus
b) -particle scattering Quantized electron orbit
c) Photoelectric effect The nuclear atom
d) Emission spectra
Quantization of energy
98. Which of the following statements is/are correct?
a) Isotopes have same number of nucleons
b) Isobars have same number of protons
c) Isotones have same number of neutrons
d) Isobars are atoms of different elements with same
isotopic number
99. If the energy of electron in H atom is given by expression, KJ mol then the energy required
to excite the electron from ground state to second
orbit is
a) 328 kJ b) 656 kJ c) 984 kJ d) 1312 kJ
100. The wavelength of first spectral line in the Balmer series is 6561 A°.
Calculate the wavelength of the
second spectral line in the Balmer series.
a) 4960A° b) 4870A° c) 4860A° d) 4970A°
101. Which of the following statements is incorrect?
a) The energy of radiation increases with decrease in
wavelength
b) The spectrum of H atom is exactly same as that of He ion
c) Energy of radiation increases with increase in ¼
d) The frequency of radiation is related to wave
number as y=Cv
102. When atoms of the gold sheet are bombarded by a
beam of -particles, only a few a -particles get
deflected whereas most of them go straight undeflected. This is
because
a) the force of attraction on a -particles by the
oppositely charged electron is not sufficient
b) the nucleus occupies much smaller
volume as compared to the volume of atom
c) the force of repulsion on fast moving a
-particles is very small
d) the neutrons in the nucleus do not have
any effect on a -particles.
ELITE SERIES for Jr. ICON Students
17|
 JEE MAINOBJECTIVE
Atomic Structure CHEMISTRY JA
light false?
following statementsconcerning
01 Which ot the cnergy b) It cannot be deflected hy amagnet
fom of d) It is a part of electromagnetic spectrum
a) isa photons of same
cnergy
c) lt consists of
of the atom?
following gave the ideaof anucleus
l04 Which of the b) Davisson and Germer's experiment
drop experiment
a) Oil d) Austen's mass spcctrogram cxperiment
scattering experiment
c) a-ay
rays?
wrong about anode
10$. What is constant
is
a)Their c/m ratio magnetic field
They are deflected by electrical and residual gas
b) of molecules of the
produced by ionization
c) They are gas
depends on nature of residual
d) Their cm ratio radiations?
following is not a characteristic of Plank's quantum theory of
106. Which of the
associated with energy
a) Radiations are to hy
Magnitude of energy associated with a quantum is equal
b) continuously
neither emitted nor absorbed
c) Radiation energy is energy
more than a quantum of
d) A body can emit less or
charge to mass ratio as
107.Cathode rays have same d) Protons
b) B-rays c) Anode rays
a) a -particles
maximum energyis
in H atom that willemit
108. The transition of electron d) n, ’ ns
c) ns ’ n4
a) n, ’n, b) n, ’N3
jumps from ls to 2s orbital.
109.In H atom when electron b) energy is absorbed
released
a) energy is d) size of the atom decreases
cation
c) the atom becomes electromagnetic spectrum
region of
hydrogen spectrum, the series of lines appearing in ultra violet
110. In
are called d) Brackett lines
c) Pfund lines
a) Balmer lines b) Lyman lines

111.Which of the following is wrong?

b) e/m ratio of anode rays is not constant
constant e/m ratio
a) Cathode rays have
constant d) e/m ratio of B-particles is constant
c) e/m ratio of protons is not
circular orbits of radius r and 4r
atoms A and B the electrons move around the nucleus in
112. In two H revolution is
them to complete one
respectively. The ratio of the times taken by d) 2:1
b) 1:2 c) 1:8
a) 1 :4
He should be
energy of Hatom is 13.6 eV, then the second ionising energy of
113.If ionising predicted.
c) 54.4 eV d) Cannot be
a) 13.6 eV b)27.2 eV
light is approximatel
of electron in the first orbit of H-atomas compared to that of velocity of
114. Velocity
| th 1 th | th d) same
b) 137 c)
a 10
1000
ICON Students
18
-ELITE SERIES for Jr.
 es MAIN OBJECTIVE CHEMISTRY IAS Atomic Structure
Ms The transition in He* ion that would have the same wave number as the first Lyman line in hydrogen
spectrum is
a) 21 b) 5’3 c) 4’2 d) 6’4

|16. With inereasing principle quantum number, the energy diference between adjacent energy levels in
H atom
a) decreases b) increases c) remains constant
)decreases for loW value of Z and increases for higher value of Z

|17. For the electronic transition from n=2’n=l which of the following will produce shortest
wavelength?
a) H atom b) D atom c) He ion d) Li?* ion
I18. In the atomic spectrum of hydrogen, the spectral lines pertaining to electronic transition of n=4 to
n=2 refers to
a) Lyman lines b) Balmer lines c) Paschen lines d) Brackett lines
119. C.C differ from each other in number of
a) electrons b) photons c) protons d) nucleons

120.A certain metal when irradiated to light (v = 3.2 x 1016 Hz) emits photoelectrons with twice kinetic
energy as did photo electrons when the same metal is irradiated by light (v = 2.0 x106 Hz). The v,
a) 1.2 x 1014 Hz b) 8 x 1015 Hz c) 1.2 x 10!6 Hz d) 4 × 10!2 Hz
121.The ratio of the ionization energy of H and Be+ js
a) 1:1 b) 1:3 c) 1:9 d) 1: 16
122. The ratio of the radii of the first three Bohr orbit in H atom is
1
b) 1:2:3 c) 1:4:9 d) 1:8:27

123. The spectrum of helium is expected to be similar to that of

a) H b) Lit c) Na d) Het
124.The energy of hydrogen atom in its ground state is -13.6eV. The energy of the level corresponding
to the quantum numnber n = 5 is
a) -0.544 eV b) -5.40 eV c) -0.85 eV d) -2.72 eV
125.The electron in an atom
a) moves randomly around the nucleus
b) has fixed space around the nucleus
c) is stationary in varius energy levels
d) moves around its nucleus in definite energy levels
126. The radius of hydrogen atom in the ground state is 0.53A", the radius of L in the similar state is
a) 1.06Ao b) 0.265A° c) 0.17A° d) 0.53A°

127. The ratio of specific charge of a proton and an o - particle is

a) 2:1 b) 1:2 c) 1:4 d) 1:1
ELITE SERIES for Jr., ICON Students 19
Atomic Structure PJEE MAIN OBJECTIVE
128.In hydrogen atom, energy of first excited state is -3.4eV. Find out the K.E. of the
CHEMISTRY
IA
hydrogen atom same orbit of
a) +3,4 eV b) +6.8 eV c) -13.6 eV d) +13.6eV
129.In a hydrogen atom, if the energy of an electron in the ground state is 13.6eV, then that in the
excited state is 2nd
a) -1.51 eV b) -3,4 eV c) -6.04 eV d) -13.6 eV
130. The ratio between kinetic energy and the total energy of the electrons of hydrogen atom
to Bohr's model is
c) 1:-1
according
a) 2: 1 b) 1:1 d) 1:2
131.If the speed of electron in Bohr first orbit of hydrogen atom be x, then speed of the electron in 2n
orbit is
a) x/9 b) x/3 c) 3x d) 9x

132. Which of the following relates to photons both as wave motion and as stream of particles?
a) Interference b)E =mc² c) Diffraction d) E = hv

133.The wave number of first line of Balmer series of hydrogen is 15200 cm'. The wave number of the
first Balmer line of Li2+ ion is
a) 15200 cm-! b) 60800 cm-1 c) 76000 cm-! d) 136,800 cm-!

134. What transmission in the hydrogen spectrum would have the same wavelength as the Balmer transition
n=4to n=2 in the He* spectrum?
a) n=4 to n= 1 b)n =3to n = 2 c) n=3 to n= 1 d) n=2to n =1

135. The energy of an electron in the first Bohr orbit of H atom is -13.6eV. The possible energy value (s)
of the excited state(s) for electron in Bohr orbits of hydrogen is (are)
b) 4.2eV c) -6.8eV d) +6.8e V
a) -3.4eV
the metal emits Y electrons
136.Light of wavelength 2 of shines on a metal surface with intensity X and
to Y andZ if 2 is halved?
per second of average energy Z. What will happen
a) Y willincrease and Z will decrease
b) Z will increase and Y remains constant
d) Y will decrease and Z will increase
c) Z willdecrease and Y remains constant
from 5 to 1shell then the wrong option is
137. In a sample of hydrogen gas the electrons are de excited

a) Total number of spectral lines = 10

=3
b) Number of spectral lines in Balmer series
Humphrey series
c) Any spectral lines are not formed in
d) Spectral lines are formed in pfund series
is 3 x 10- J. Calculate its wave length?
138.The mass of an electron is 9.1x10-kg. If its K.E 4) 890 nm
b) 899nm c) 898.7nm
1) 896.7nm
a distance
emploved to locate an electron in an atom with in
159.A microscope using suitable photons is velocity?
of its
of 0.1Aº What is the uncertainty involved in measurement m.s-l
c) 5.8 x 10 m.s-! d) 5.8 x 10-7
a) 5.8 x 10 m.sec-l b) 5.79 x 106 m.s-l
ICON Students
20
ELITESERIES for Jr.
 EE MAINOBJECTIVE CHEMISTRY IA Atomic Structure
40. A
golf ball has a mass of 40g and speed of 45m/sec. If the speed can be measured with in accuracy
of 0.2%. The uncertainty in the position is x x 10-35 m. What is the value of 'x*?
141.What is the lowest value of 'n' that allows 'g' orbitals to exist?
42. An atom of an element contains 29 electrons and 35 neutrons. Calculate the number of protons in an
atom?

143. An atomic orbitals has n=3; what are the possible value of m?
J44.How many number of the following sets of quantum numbers are not possible?
A :n=0, l=0, m =0 B:n=1, l= 0, m=0
C:n=1, I=1, m=0 D:n=2, l= 1, m=0
E:n=3, l=3, m=-3 F:n=3, l=1, m=0
145. Similar to electron diffraction, neutron diffraction microscopes are used for the determination of the
structure of molecules. If the wavelength here is 800Dm, calculate the characteristic velocity associated
with the neutron?

146.If the position of the electron if measured with in an accuracy 0.002nm. Calculate the uncertainty in
the momentum of the electron.
a) 2.637 >x 102 kg msec-! b) 3.637x 1024 kg msec-1
c) 1.638 x 1024 kg msec-! d) 2.82 x 1023 kg msec-l
147. The quantum numbers are given below, arrange them in order of increases energies -
(1) n= 4, l= 2, m= -2 (2) n =3, l= 2, m= 1
(3) n =4, l= 1, m = 0 (4) n =3, l= 2, m =-2
(5) n = 3, l= 1, m =-1 (6) n = 4, l=1, m =0
a) 5<2=4<3=6<1 b) 5<2<4<3<6<1 c) 5<4<2<3<l<6 d) 5<4=2<l<3=6
148. The bromine atom possesses 35 electrons. It contains '6° electrons in 2p orbitals, '6 electrons in 3p
orbital and 's' electrons in 4p orbitals. Which of these electrons the lowest effective nuclear charge?
a) 2p b) 3p c) 4p d) none

149. Among the following pairs of orbitals incorrectly arranged the larger effective nuclear charge?
a) 2s > 3s b) 4d > 4f c) 3p > 3d d) 4f > 4d
150. The unpaired electrons in Al and Si are present in 3p-orbitals
1ST.The sum of the number of unpaired electrons in (a) Cr, (b) Fe, (c) Kr
152. The momentum of a photon of frequency 5 x 10" s is nearly
a) 1.1x 10-24 kgm.sl b) 3.33 x 1048 kgm.s-1
c) 2.27 x 10-40 kgm.s d) 2.27 x 10-38 kgm.s-!
1D3.Krypton (Kr) has the electronic configuration [Ar]4s'3d!"4p, the 37 electron will go in to which
of the fallowing subshell
a) 4f b) 4d c) 3p d) 5s
ELITE SERIES for Jr. ICON Students 21
|Atomic Structure JEE MAIN OBJECTIVE
CHEMISTRY IA
154 Whrch of fallowing graphs correspond to one node?

b) c) dy

158.The number of nodes present in 4f-orbitals

a) 3 b) zero c) 2 d) 1
156.The orbital angular momentum of an electron in p-orbitals is
1h
a) zero
b) J2 c) 2T d)
22T
KEY SHEET

1) a 2) c 3) b 4) a 5) c 6) b 7) c 8) c 9) d 10) a
11)c 12) d 13) a 14) d 15) a 16) a 17) b 18) c 19) a 20) c
21) d 22) a 23) c 24) a 25) b 26) c 27) d 28) b 29) d 30) c
31) d 32) a 33) a 34) c 35) a 36) b 37) d 38) a 39) c 40) b
41)c 42) a 43) d 44) a 45) b 46) d 47) a 48) 6626 49) a 50) 9
51) b 52) d 53) 18 54) 17 55) 2 56) d 57) 16 58) 455 59) 332 60) 4

61) 16 62) a 63) a 64) c 65)c 66) c 67) d 68) a 69) a 70) a

71)b 72) c 73) b 74) b 75) b 76) b 77) d 78) a 79) c 80) b

81) a 82) c 83) c 84) b 85) c 86) b 87) c 88) b 89) d 90) c

91) c 92) b 93) a 94) c 95)a 96) b 97) d 98) c 99) c 100) c
101) b 102) b 103) c 104) c 105) a 106) d 107) b 108) a 109) b 110) b

111) c 112) c 113) c 114) b 115) c 116) a 117) d 118) b 119)d 120) b
121) d 122) c 123) b 124) a 125) d 126) c 127) a 128) a 129) a 130) c

131) b 132) d 133) d 134) d 135) a 136) b 137) d 138) a 139) b 140) 146

141)5 142) 29 143) 9 144) 3 145) 494 146) a 147) a 148) c 149) d 150) 3

151) 10 152) a 153) d 154) b 155) b 156) b

22 ELITE SERIES for Jr. ICON Students

 JEE MAIN OBJECTIVE CHEMISTRY IA S Atomic Structure

PREVIOUS YEARQUESTIONS
Stralght Objective and Numerical / integer Type Questions
I the Thomson model of the atom was correct, then the result of Rutherford's gold foil experiment
would have been (2021, 27 July Shift-II]
a) All of the -particles pass through the gold foil without decrease in speed
b) a-particles are detlected over a wide range of angles
c) All a-particles get bounced back by 180°
) a-particles pass through the gold foil deflected by small angles and with reduced speed
Hydrogen has three isotopes (A), (B) and (C). If the number of neutron (s) in (A), (B) and (C)
respectively, are (x), (y) and (2), the sum of (x), (y) and (z) is [2020, 8 Jan. Shift-II]
a) 4 b) 3 c) 2 d) 1
Consider an imaginary ion X. 22
The nucleus contains a'% more neutrons than the number of
electrons in the ion. The value of 'a' is (nearest integer) [2020, 26 July Shift-I)

The minimum energy that must be possessed by photons in order to produce the photoelectric
efect with platinum metal is [Given, the threshold frequency of platinum is 1.3 x 10' s and
h= 6.6 x 10-34 Js] [2022, 25 June Shift-II]
a) 3.21 x 10-14 J b) 6.24 x 10-l6 J c) 8.58 x 10-19 J d)9.76 x 10-20 J
5. The energy of one mole of photons of radiation of wavelength 300 nm is : [Given, h=6.63 x 10-4 Js,
N, = 6.02 x 10 mol,c=3x 108 ms-] [2022, 24 June Shift-II]
a) 235 k mol-! b) 325 kJ mol-! c) 399 kJ mol-l d) 435 kJ mo-!

6. What is the work function of the metal, if the light of wavelength 4000Ã generates photoelectron of
velocity 6 x 10 ms-l from it?
(Mass of electron 9 x 10-31 kg velocity of light 3x 108 ms-, Planck's constant 6.626 x 10-34 Js,
Charge of electron 1.6 x 10-19 JeV-!) [2019, 12 Jan]
a) 4.0 eV b) 2.1 eV c) 0.9 eV d) 0.9 eV

7 Which of the graphs shown below does not represent the relationship between incident light and the
electron ejected from metal surface? s [2019,10 Jan]
e s
s s of e
e e
of Number of
of K.E.
K.E. K.E.

a) b) c) d)
+Frequency Frequency
> Energy of light +Intensity of of light light
8. If , and 2. be threshold wavelength and wavelength of incident light, the velocity of photoelectron
ejected from the metal surface is: [Jee Main 2014]

2hc
-(g-)
2he(g -
a)
m -) b)
m
d)

ELITE SERIES for Jr. ICON Students 23

Atomic Structure JEE MAIN OBJECTIVE CHEMISTRY IA
9. Which of the following statements is false? |Jee Main 2018]
a) Photon has momentum as well as wavelength.
Stark effect
b) Splitting of spectral lines in electrical field is called
c) Frequency of emitted radiation from a black body goes from a lower wavelength to higher
wavelength as the temperature increases.
d) Rydberg constant has unit of energy.
that
10. lonization energy of gaseous Na atoms is 495,5 kJ mol". The lowest possible frequency of light
ionizes a sodium atom is : (h = 6.6326 x 10-4 Js, N, = 6.022 x 102 mol-) [Jee Main 2014]
a) 7.50 x 104 -! b) 4.76 x 10!4 s-l c) 3.15 x 10'5 s-! d) 1.24 x 10!5 _-l
as
|1, Given below are two statements, one is labeled as Assertion (A) and the other is labeled
Reason (R).
Assertion (A) : In the photoelectric effect, the electrons are ejected from the metal surface as soon
as the bulb of light of frequency greater than threshold frequency strikes the surface.
Reason (R) : When the photon of any energy strikes an electron in the atom, transfer of energy from
photon to the electron takes place.
In the light of the above statements, choose the appropriate answer from the options given below.
[2023, 11 April]
a) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
b) Both (A) and (R) are correct and (R)is the correct explanation of (A)
co (A) is correct but (R) is not correct
d) (A) is not correct but (R is correct

12. The energy of one mole of photons of radiation of frequency 2 x 10" Hz in J mol is (Nearest
integer) [Given, h = 6.626 x 10-34 Js, N, = 6.022 x 10 mol [2023, 30 Jan. Shift-II]
13. If the work function of a metal is 6.63 x 10-19 J, the maximum wavelength of the photon required to
remove a photoelectron from the metal is nm. (Nearest integer]
[Given, h=6.63 × 10-34 Js and c =3x 10 ms] [2022, 28 June Shift-I]
14. The longest wavelength of light that can be used for the ionization of lithium atom (Li) in its ground
state is x × 10 m. The value of x is [Nearest integer] (Given; energy of the electron the first
shell of the hydrogen atom is 22 x 10-8 J; h= 6.63 x 1034 Js and c =3 x 108 ms-l)
[2022, 25 June Shift-1]
15. A50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons
emitted per second bythe bulb is x x 1020 The value of x is
[Given, h = 6.63 x 10-34 Js and c = 3.0 x 108 ms-l] [2021, 1 Sep. Shift-II]
l6. The number of photons emited by a monochromatic (single frequency) infrared range finder of
power I m W and wavelength of 1000 nm, in 0.1 second is x x 10!3, The value of x is (Nearest
integer) (Given, h =6.63 × 10-34 Js and c= 3.00 x 10 ms-l, [2021, 27 Aug, Shift-II]
17. Ametal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric
current is 43 x 10 Hz. The velocity of ejected electron is x 10° msl. (Nearest integer)
[Use h=6.63 x 10-% Js, m, =9.0 x 10-3 kgl [2021,26 Aug. Shift_II]
24 S ELITE SERIES for Jr. ICON Students
 EE MAIN OBJECTIVE CHEMISTRY IA bh Atomic Structure

8. ASource of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in

10seConds. When this radiation falls on the surface of sodium, x x l020 clectrons are cjected per
rond. Assume that wavelength 400 nm is sufficient for cjection of electron from the surface of
slium metal. the value of xis_ (Nerest integer) (h =6.626 x 10" Js) (2021, 25 July Shift-I1)|
The work function of sodium metal is 4.41 x10-9 J. If photons of wavelength 300 nm are incident
on the metal, the kinetic energy of the ejected electrons will be x 102 J.
(h =6.63 x 10- Js, c=3x 108 m/s) [2020, 2 Sep. Shift-II]

o The nunmber of incorect statement/s about the black body-from the following is
[2023, 10 Apr. Shift-I)
A)Emit or absorb energy in the form of electromagnetic radiation.
B)Frequency distribution of the emited radiation depends of temperature.
C)At a given temperature, intensity vs frequency curve passes through a maximum value.
D)The maximum of the intensity vs frequency curve is at a higher frequency at higher t emperature
compared to that at lower temperature.
(2023, 12 Apr. Shift-I]
D1. Value of work function (W) for a few metals are given below.
Metal Li Na K Mg Cu Ag
W,JeV 2.42 2.3 2.253.7 4.8 4.3
The number of metals which will show photoelectric effect when light ofwavelength 400 nm falls
on it is _(Given, (h = 6.6 x1034 Js, c=3× 10 ms-, e = 1.6x 10-l9 C)

22. The shÍrtest wavelength of hydrogen atom in Lyman series is . The longest wavelength in Balmer
series of Het is [2023, 29 Jan. Shift-II]

5 52 367.
a) 92. c) d) 5

D3. Which transition in the hydrogen spectrum would have the same wave length as the Balmer type
transition from n = 4 to n = 2 of Het spectrum [2023, 31 Jan. Shift-II]
a) n=1to n =3 b) n=1to n= 2 c) n=3to n =4 d) n=2to n= 1

[2020, 4]
04. The region in the electromagnetic spectrum of the Balmer series lines appear is
a) Infrared b) Ultraviolet c) Microwave d) visible
Balmer
25. The shortest wavelength ofH atom in the Lyman series is y. The longest wavelength in the
series of He is [2020, 4]

3624 51 92,
a) b c) 5 d) 5
9
6. For any given series of spectral lines of atomic hydrogen, let AV = V -Vin be the difference in
max

maximum and minimum frequencies in cm. The ratio of Avjvnan to AVplner is

[2019, 9 Apr. Shift-II)
a) 27:5 b) 5:4 e 94 d) 4:1

ELITE SERIES for Jr. ICON Students 25

 Atomic Structure JEE MAIN OBJECTIVE CHEMISTRY IA
27. For emission line of atomic hydrogen from n, 8to n, n, the plot of wave number (v) against
will be (The Rydberg constant, Ry is in wave number unit) (2019, 9 Apr. Shift-I
a) Non linear bYLinear with slope - Ry
c) Linear with slope Ru d) Linear with intercept - Ry
28. The limiting line in Balmer series will have a frequency of (Rydberg constant, R = 3.29 x 10s
cycles/s)
b) 3.29 >x 1015
[AIEEE 2012]
a) 8.22 x 1014 s-! c) 3.65 x 1014 s-l d) 5.26 x 1013 s-1
29, The figure that is not a direct manifestation of the quantum
of nature of atoms is [2020, 2 Sep. Shift-In
Kinetic
energy
Photoelectrons
Rb K Na

a b

Frequency of incident radiation

Internal
intensity
energy of black body
c) of Ar 300 400 500 600 d radiation

Temeprature (K) Wavelength

30. The number of following statement/s which is/are incorrect is [2023, 8 Apr. Shift-II]
a) Line emission spectra are used to study the electronic structure.
b) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red
to violet.

c) An absorption spectrum is like the photographic negative of an emission spectrum.

d) The element helium was discovered in the sun spectroscopic method.
31. When the excited electron of a H-atom from n = 5 drops to the ground state, the maximum number
emission lines observed are (2022, 25 July Shift-I]
32. Given below are two statements.

Statement-I : According to Bohr's model of hydrogen atom, the angular momentum of an electron
in a given stationary state is quantized.
Statement-II : The concept of electron in Bohr's orbit, violates the Heisenberg uncertainty principle.
In the light of the above statements, choose the most appropriate answer from the options given
below. [2023, 15 Apr. Shift-I]
a) Statement-I is incorrect by Statement-II is correct.
b) Statement-I is correct by Statement-II is incorrect.
c) Both Statement-I and Statement-II are incorrect.
dy Both Statement-I and Statement-II are correct.
26 ELITE SERIES for Jr. ICON
Students
 JEE MAIN OBJEC TIVE CHEMISTRY IA
Atomic Structure
. Theenergy of an clectron in the first Bohr orbit of hydrogen atom is -2, 18 x 10-14I. its energy in the
is
thind Bohr orbit (2023, 13 Apr. Shift-1}|
value
a) Thrcc time of this b) Gth of this value
value
c) One third of this of this value
27
4, Ifthe radius of the first orbit of hydrogen atom is ah, then de-Broglie's wavelength of electron in
3d orbit is : [2023, 16 Apr. Shift-1)
b)
Tta
a) 3ra, 3 c) 6a d) 6
15, Iftheradius of the 3rd Bohr's orbit of hydrogen atom is r, and the radius of 4h Bohr's orbit is r,. Then
[2022, 26 June Shift-1]
9 16 3
c) I4 =75
k Given below are two statement.
Statement-I : According to Bohr's model of atom, qualitatively the magnitude of velocity of electron
increases with decrease in positive charges on the nucleus as there is no strong hold on the electron
by the nucleus,
Statement-Il :According to Bohr's model of an atom, qualitatively the magnitude of velocity of
electron increases with decrease in principal quantum.
In the light of the above statements, choose the most appropriate answer from the options given
below. [2021, 26 Aug, Shift-I]
a) Both statement-I and Statement-II are false. b) Both Statement-I and Statement-II are true.
c) Statement-I is false but Statement-II is true. d) Statement-I is true but Statement-II is false.
27 Given below are two statements.
Statement-I :Rutherfod's gold foil experiment cannot explain the linespectrum of hydrogen atom.
Statement-II: Bohr's model of hydrogen atom contradicts Heisenberg's uncertainty principle.
In the light of the above statements, choose the most appropriate answer from the option given
below. (2021, 27 July Shift-I]|
a) Statement-I is false but Statement-II is true b) Statement-I is true but Statement-II is false.
c) Both statements-I and Statement-II are false. d) Both statement-I and Statement-II are true.
38. According to Bohr's atomic theory,
I) Kinetic energy of electron is oc

I) The product of velocity (v) of electron and principal quantum number (n), 'v x n' «Z
z?
II) Fequency of revolution of electron in an orbital o

V) Columbic force of attraction on the electron oc

n

Choose the most appropriate answer from the options given below. [2021, 18 March]
a) Only III b) Only I .Í, III and IV d) Iand IV
ELITE SERIES for Jr. ICON Students F 27
 Atomic Structure JEE MAIN OBJECTIVE CHEMISTRY IA
30, The radius of the second Bohr orbit in terms of the Bohr radius, ap, in Li2* is :
(2020, 8 Jan. Shift-)

b) c) dy
3 9

40. The ground state energy of hydrogen atom is -13.6eV. The energy of second excited state
of Hat
ion in eV is: [2019, 10 Jan. Shift-I)
a) -s4.4 b) -3.4 c) -6.04 d) -27.2

41. The radius of the second Bohr orbit for hydrogen atom is (Planck's constant (h) = 6.6262 x 10J
mass of electron =9.1091 x 10- kg, charge of electron (e) =1.60210 x10""C, permittivity of vacuum
(E,) =8.854185x10- kg'mA') (Jee Main 20171
a) 1.65 b) 4.76Å c) 0.529 A d) 2.12
42. Which of the following is the energy of a possible excited state of hydrogen? (Jee Main 2015]
a) +13.6 eV b) -6.8 eV c) -3.4 eV d) +6.8 eV

43. The energy of an electron in first Bohr orbit of H-atom is -13.6 eV. The energy value of electron in
the excited sate of Li?t is [Jee Main, 2010, 2014]
a) -27.2 eV b) 30.6 eV c) -30.6eV d) 27.2 eV

44. If m and e are the mass and charge of the revolving electron in the orbit of radius r for hydrogen
atom, the total energy of the revolving electron will be (Jee Main 2014]
me? le
a) b) c) d)
2 r 2 T

45. Energy of an electron is given by E=-2.178 x10lsy wave length of light required to excite
an electron in an hydrogen atom from level n = 1 to n = 2 will be :
(h= 6.62 x 10-34 Js and c = 3.0 x 10® ms-) (Jee Main 2013)
a) 1.214 x 10- m b) 2.816 x10-7 m c) 6.500 x 10-7 d) 68.500 x 107
46. lonization energy of Het is 19.6 x 10-15 J atom. The energy of the first stationary state (n = 1) of
Li2 is [AIEEE2010]
a) 8.82 x10-" Jatom b) 4.41x10-l6 Jatom-!
c) 4,41x10-"Jatom-l d) -2.2x10-5Jatom-l
47. The ionization enthalpy of hydrogen atom is 1.32 x 10° J mol-', The energy required to excite the
electron in the atom from n=l to n=2 [AIEE 2008]
a) 9.84 x 105 J molH b) 8.51 x 10 J molH c) 6.56 x 105 J mol-1 d) 7.56 x 105 J mol-!
48. According to Bohr's theory, the angular momentum of an electron in 5lh orbit is [AIEE 2006]
a)254 b)1.04 c)

28
ELITE SERIES for Jr. ICON Students