JEE
MANZIL JEE(2025)
Chemistry
DPP: 21
Structure of Atom
Q1 The fraction of volume occupied by the nucleus should be
with respect to the total volume of an atom is (A) 2.188 × 10
6
m/s
(A) 10
−15
(B) 6.564 × 10
6
m/s
(B) 10
−5
(C) 7.293 × 10
5
m/s
(C) 10 −30
(D) 7.293 × 10
6
m/s
(D) 10
−10
Q6 Which of the following quantity for an electron
Q2 The distance of closest approach of an α-particle revolving around the H− nucleus is independent
fired towards a nucleus with momentum ' P ' is r . to the mass of electron?
What will be the distance of closest approach (A) Distance from nucleus
when the momentum of the α-particle is 2P ? (B) Kinetic energy
(A) 2r (C) Potential energy
(B) 4r (D) Speed
(C) r/2
Q7 The energy of an excited H-atom is −1.51eV .
(D) r/4
Angular momentum of e − in the given orbit will
Q3 α -particles are projected towards the nucleus of be
following metals with the same kinetic energy. (A) 3 h/π
Towards which metal, the distance of closest (B) 3 h/2π
approach will be minimum? (C) 2 h/π
(A) Cu(Z = 29) (D) h/π
(B) Ag(Z = 47)
Q8 The radius of an orbit of Be+3 ion is 0.529Ao .
(C) Au(Z = 79)
The velocity of electron in this orbit will be
(D) Ca(Z = 20)
(A) 0.545 × 106 m/s
Q4 Rutherford's experiment which established (B) 2.18 × 10 6
m/s
the nuclear model of the atom, used a beam of (C) 4.36 × 10 6
m/s
(A) β -particles, which impinged on a metal foil (D) 1.09 × 10 6
m/s
and got absorbed.
Q9 For which transition in H-atom, the amount
(B) γ-rays, which impinged on a metal foil and
of energy released will be maximum?
ejected electrons.
(A) n = 4 to n = 2
(C) helium atoms, which impinged on a metal foil
(B) n = 5 to n = 2
and got scattered.
(C) n = 2 to n = 1
(D) helium nuclei, which impinged on a metal foil
(D) n = 7 to n = 2
and got scattered.
Q10 Choose the incorrect relation on the basis
Q5 An electron revolves round Li2+ nucleus at a
of Bohr's theory
distance of 1.587Ao . The speed of electron
(A) Velocity of electron ∝ 1
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(B) Frequency of revolution ∝ 1
2
Q15 A bulb of 40 W is producing a light of
n
(C) Radius of orbit ∝ 2
n Z wavelength 620 nm with 80% of efficiency then
(D) Force on electron ∝ 1
the number of photons emitted by the bulb in 20
4
n
seconds are
Q11 Bohr's radius of 2nd orbit of Be is equal to
3+
(A) 2 × 10
18
that of (B) 10
18
(A) 4th orbit of hydrogen (C) 1021
(B) 2nd orbit of He+ (D) 2 × 1021
(C) 3rd orbit of Li2+
(D) First orbit of hydrogen Q16 Which of the following is an incorrect
graphical representation based on photoelectric
Q12 The speed of electron revolving in the fourth effect?
orbit of a hydrogen-like atom or ion is (A)
1094 km/s . The atom or ion is
(A) H
(B) He
+
(C) Li2+
(D) Be3+
(B)
Q13 Which of the following statements is false?
(A) The energy of red photon is more than the
energy of violet photon
(B) The momentum of photon is inversely
proportional to its wavelength
(C) The energy of a photon is inversely (C)
proportional to its wavelength
(D) The particle nature of electromagnetic
radiations is able to explain the photoelectric
effect
(D)
Q14 Certain sun glasses having small amount of
AgCl incorporated in the lenses, on exposure to
light of appropriate wavelength turns to Gray
color to reduce the glare following the reactions
hv
AgCl ⟶ Ag( Gray ) + Cl
Q17 The number of possible spectral lines in
If the heat of reaction for the decomposition of
Brackett series in hydrogen spectrum, when the
is 248 , what maximum
−1
AgCl kJ mol
electrons present in the ninth excited state return
wavelength is needed to induce the desired to the ground state, is
process? (A) 36 (B) 45
(A) 4.83 × 10−7 m
(C) 5 (D) 6
(B) 2.45 × 10−7 m
(C) 4.83 × 10−8 m Q18 In a sample of H-atom electrons make a
(D) 7.83 × 10−7 m transition from 5th excited state to the ground
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state, producing all possible types of photons, Q24 The circumference of the third orbit of He+ ion is
then the number of lines in the infrared region xm . The de-Broglie wavelength of electron
are revolving in this orbit will be
(A) x
m
Q19 Calculate wavelength of 3 rd line of Brackett 3
(B) 3 x m
series in hydrogen spectrum
(C) x
m
(A) 784 9
33 R
(D) 9 x m
(B)
33 R
784
(C) 784 R
33
Q25 Which orbital is represented by ψ4,2,0 ?
(D) 33
(A) 4d
784 R
(B) 3d
Q20 What is the frequency of the second line of the (C) 4p
Paschen series in the spectrum of He ion?
+
(D) 4s
(A) 64 R.C
225
(B) 64R
225
(C) 225
64R
(D) 225C
64R
Q21 Uncertainty in the position of an electron ( mass
= 9.1 × 10
−31
kg) moving with a velocity 300
m/s accurate up to 0.001% will be
(A) 5.76 × 10−3 m
(B) 1.92 × 10−2 m
(C) 3.84 × 10
−3
m
(D) 19.2 × 10 −4
m
Q22 Which of the following configuration is violating
Pauli's exclusion principle?
(A)
(B)
(C)
(D) (B) and (C)
Q23 The magnetic moment order is correctly given in
(A) Fe2+ < Fe
3+
< Mn
4+
< Cr
3+
(B) Cr3+ = Mn
4+
< Fe
2+ 3+
< Fe
(C) Cr3+ = Mn
4+
< Fe
3+
< Fe
2+
(D) Fe2+ < Cr
3+
< Fe
3+
< Mn
4+
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Answer Key
Q1 (A) Q14 (A)
Q2 (D) Q15 (D)
Q3 (D) Q16 (C)
Q4 (D) Q17 (D)
Q5 (A) Q18 6
Q6 (D) Q19 (A)
Q7 (B) Q20 (A)
Q8 (C) Q21 (B)
Q9 (C) Q22 (B)
Q10 (B, C) Q23 (B)
Q11 (D) Q24 (A)
Q12 (B) Q25 (A)
Q13 (A)
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