# Atoms MCQ Questions Class 12 Physics Chapter 12

Atoms MCQ Questions Class 12 Physics Chapter 12

NCERT MCQ Questions for Class 12 Physics Chapter 12 Atoms. Atoms MCQ Questions with Answers from Class 12 Physics.

## Atoms MCQ Questions Class 12 Physics Chapter 12

Atoms Multiple Choice Questions with Answers Class 12 Physics Chapter 12 PDF is available.

Multiple Choice Questions:

1) The first model of atom was proposed by J J Thomson which is called as

a) Atomic model

b) Plum pudding model

c) Nuclear model

d) Both a and b

Ans: b) plum pudding model

2) Rutherford’s planetary model of atom is also called as

a) Atomic model

b) Plum pudding model

c) Nuclear model of the atom

d) None

Ans: c) nuclear model of the atom

3) According to Rutherford’s nuclear model of atom, the entire positive charge and most of the mass of the atom is concentrated in a small volume called as

a) Centre of atom

b) Nucleus

c) Electrons

d) Nucleons

Ans: b) nucleus

4) The dark lines correspond to those wavelengths which were found in the emission line spectrum of the gas, which is called as

a) Emission spectrum of the material of the gas

b) Absorption spectrum of the material of the gas

c) Both a and b

d) None

Ans: b) absorption spectrum of the material of the gas

5) The Balmerformula is given by

a) 1/wavelength = R*(1/22 + 1/n2)

b) Wavelength = R*(1/22 – 1/n2)

c) 1/wavelength = R*(1/22 – 1/n2)

d) None

Ans: c) 1/wavelength = R*(1/22 – 1/n2)

6) The value of Rydberg constant R is given as

a) 1.097*10-7 m-1

b) 1.097*107 m-1

c) 1.097*10-8 m-1

d) 1.097*1017 m-1

Ans: b) 1.097*107 m-1

7) For Lyman series n=

a) n= 1,2,3,..

b) n= 2,3,4..

c) n= 4,5,6..

d) None

Ans: b) n = 2,3,4…

8) For Paschen series n=

a) n= 2,3,4…

b) n= 4,5,6…

c) n= 5,6,7…

d) None

Ans: b) n= 4,5,6..

9) For Bracket series n=

a) n= 4,5,6…

b) n= 6,7,8…

c) n= 5,6,7…

d) None

Ans: c) n= 5,6,7…

10) For Pfund series n=

a) n = 6,7,8…

b) n= 5,6,7…

c) n= 7,8,9…

d) None

Ans: a) n= 6,7,8,…

11) Lyman series is in the

a) Visible region

b) Infrared region

c) Ultraviolet region

d) None

Ans: c) ultraviolet region

12) The Paschen, Bracket and Pfund series is in the

a) Visible region

b) Ultraviolet region

c) Infrared region

d) None

Ans: c) infrared region

13) An electron in an atom could revolve in a certain stable orbits without the emission of radiant energy, this is

a) Bohr’s second postulate

b) Bohr’s first postulate

c) Rutherford’s first postulate

d) Rutherford’s second postulate

Ans: b) Bohr’s first postulate

14) Electron revolves around the nucleus only in those orbits for which the angular momentum is some integral multiple of

a) h/2

b) h/4π

c) h/2π

d) 2π/h

Ans: c) h/2π

15) Electron revolves around the nucleus only in those orbits for which the angular momentum is some integral multiple of h/2π, this is

a) Rutherford’s first postulate

b) Rutherford’s second postulate

c) Bohr’s first postulate

d) Bohr’s second postulate

Ans: d) Bohr’s second postulate

16) According to Bohr’s second postulate, the angular momentum of the orbiting electron is

a) Not quantised

b) Quantised

c) Discrete

d) None

Ans: b) quantised

17) According to Bohr’s second postulate, the angular momentum of the orbiting electron is given by

a) L = h/2π

b) L= nh/2

c) L = nh/2π

d) L = 2π/nh

Ans: c) L = nh/2π

18) The electron make transition from higher energy orbit to lower energy orbit by emitting a photon having energy equal to the energy difference between the initial and final states, this is

a) Bohr’s first postulate

b) Bohr’s second postulate

c) Bohr’s third postulate

d) Rutherford’s first postulate

Ans: c) Bohr’s third postulate

19) The frequency n of the emitted photon according to Bohr’s third postulate is given by

a) Ei – Ef = hn

b) Ef – Ei = hn

c) Ei – Ef = h

d) None

Ans: a) Ei – Ef = hn

20) 1eV =

a) 1.6*10+19J

b) 1.6*10-19J

c) 1.6*10-27J

d) 1.6*10+27J

Ans: b) 1.6*10-19 J

21) The energy of an atom is ____ when it’s electron is revolving in an orbit closest to the nucleus.

a) Large

b) Maximum

c) Least

d) None

Ans: c) least

22) The lowest energy state of the atom is called as

a) Excited state

b) Zero energy state

c) Ground state

d) None

Ans: c) ground state

23) The minimum energy required to free the electron from the ground state of the atom is called as

a) Ground state energy

b) Ionisation energy of the atom

c) Ionisation potential

d) None

Ans: b) ionisation energy of the atom

24) At room temperature, most of the hydrogen atoms are in

a) First excited state

b) Second excited state

c) Ground state

d) None

Ans: c) ground state

25) As the excitation of hydrogen atom increases the value of minimum energy required to free the electron from the excited atom

a) Increases

b) Decreases

c) Remains same

d) None

Ans: b) decreases

26) The Bohr’s model is applicable to

a) Helium atom

b) Lithium atom

c) Hydrogen atom

d) None

Ans: c) hydrogen atom

27) Atom as a whole is electrically neutral and hence contains

a) Non equal amount of positive and negative charges

b) Equal amount of positive and negative charges

c) Only positive charges

d) Only negative charges

Ans: b) equal amount of positive and negative charges

28) The stationary orbits are those for which angular momentum is some

a) h/2π

b) Integral multiple of h/2π

c) Zero

d) None

Ans: b) integral multiple of h/2π

29) In angular momentum term L= nh/2π, n is called as

a) Orbit number

b) Shell number

c) Quantum number

d) Principal quantum number

Ans: d) principal quantum number

30) For ground state the value of principal quantum number is

a) n=0

b) n= 1

c) n= 2

d) n=-1

Ans: b) n= 1

31) Bohr’s model is only applicable to

a) Hydrogenic atoms

b) Single electron atoms

c) Both a and b

d) For any atoms

Ans: c) both a and b

Updated: April 12, 2023 — 10:45 am