## Class 12 Physics MCQs Atoms for JEE/NEET

Here, you will get Class 12 Physics MCQ of Chapter 12 Atoms for cracking JEE and NEET/AIIMS. By solving these MCQs of Class 12 Physics Chapter 12 Atoms, you will get the confidence to crack JEE or NEET. Practice MCQ Questions for Class 12 Physics with Answers on a daily basis and score well in exams.

## Atoms Class 12 MCQs Questions with Answers

The transition from the state n = 5 to n = 1 in a hydrogen atom results in UV radiation. Infrared radiation will be obtained in the transition
(a) 2 → 1
(b) 3 → 2
(c) 4 → 3
(d) 6 → 2

Rutherford’s experiments suggested that the size of the nucleus is about
(a) 10-14 m to 10-12 m
(b) 10-15 m to 10-13 m
(c) 10-15 m to 10-14 m
(d) 10-15 m to 10-12 m

Answer: (c) 10-15 m to 10-14 m

In the Geiger-Marsden scattering experiment, is case of head-on collision the impact parameter should be
(a) maximum
(b) minimum
(c) infinite
(d) zero

In Geiger-Marsden scattering experiment, the trajectory traced by an a-particle depends on
(a) number of collision
(b) number of scattered a-particles
(c) impact parameter
(d) none of these

The binding energy of a deuteron is about
(a) 2.22 MeV
(b) 2.22 J
(c) 2.22 eV
(d) None of these

Which of the following in a hydrogen atom is independent of the principal quantum number n? (The symbols have their usual meanings)
(a) νn
(b) Er
(c) En
(d) νr

The angular speed of the electron in the nth orbit of Bohr hydrogen atom is
(a) directly proportional to n
(b) inversely proportional to n
(c) inversely proportional to n2
(d) inversely proportional to n3

Answer: (d) inversely proportional to n3

In the ground state in …A… electrons are in stable equilibrium while in …B… electrons always experiences a net force. Here, A and B refer to
(a) Dalton’s theory, Rutherford model
(b) Rutherford’s model, Bohr’s model
(c) Thomson’s model, Rutherford’s model
(d) Rutherford’s model, Thomson’s model

Answer: (c) Thomson’s model, Rutherford’s model

The energy equivalent to mass defect is called
(a) binding energy
(b) internal energy
(c) external energy
(d) enthalpy

The angular momentum of the electron in hydrogen atom in the ground state is
(a) 2h
(b) h/2
(c) h/2π
(d) h/4π

For ionization of excited Hydrogen atom, the, required energy is
(a) a little less than 13.6
(b) equal to 13.6
(c) more than 13.6
(d) 3.4 or less

The principle that a quantum orbital cannot be occupied by more than two electrons was given by
(a) Pauli
(b) Millikan
(c) Hund
(d) None of these

Isotones have the same
(a) A
(b) Z
(c) N
(d) All the above

The mass of a neutron is
(a) 1.00866 u
(b) 1.0866 u
(c) 1.866 u
(d) 0.1866 u

The energy equivalent to one atomic mass unit is
(a) 1.6 × 10-19 J
(b) 6.02 × 1023 J
(c) 9.31 MeV
(d) 931 MeV

Which of the following type of radiation is not emitted by the electronic structure of atoms
(a) X-rays
(b) Visible light
(c) γ-rays
(d) Ultraviolet light

According to classical theory, Rutherford atom is
(a) stable
(b) unstable
(c) metastable
(d) semistable

When an electron jumps from some outer orb it to the innermost orbit in the hydrogen atom, the spectral line belongs to
(a) Lyman series
(b) Balmer series
(c) Paschen series
(d) Pfund series

In an atom, the two electrons move round the nucleus in circular orbits of radii R and 4R. The ratio of the times taken by them to complete one revolution is
(a) 1/8
(b) 1/4
(c) 4
(d) 8

In Rutherford’s scattering experiment with gold foil, 232 counts per minute are observed at an angle of 60°. The number of counts/min. at an angle of 120° will be
(A) 232
(b) 116
(c) 26
(d) 52

As per Bohr model, the minimum energy (in eV) required to remove an electron from the ground state of double ionized Li atom (Z = 3) is
(a) 1.51 eV
(b) 13.6 eV
(c) 40.8 eV
(d) 122.4 eV

On moving up in the energy states of a H-like atom, the energy difference between two consecutive energy states
(a) decreases
(b) increases
(c) first decreases then increases
(d) first increases then decreases

The longest wavelength in Balmer series of hydrogen spectrum will be
(a) 6557 Å
(b) 1216 Å
(c) 4800 Å
(d) 5600 Å

The ratio between Bohr radii is
(a) 1 : 2 : 3
(b) 2 : 4 : 6
(c) 1 : 4 : 9
(d) 1 : 3 : 5

Answer: (c) 1 : 4 : 9

If 13.6 eV energy is required to ionise the hydrogen atom, then energy required to remove an electron from n = 2 is
(a) 10.2 eV
(b) 0 eV
(c) 3.4 eV
(d) 6.8 eV