 # MCQs on Bohr's Atomic Model

Bohr’s atomic model was proposed by Neils Bohr in 1913. He explained the structure of hydrogen atoms. He modified Rutherford’s model of an atom and used Planck’s concept of quantisation of energy. According to this theory, electrons move around the nucleus in a circular path or orbits having fixed radius and energy. Electrons may move from a lower energy level to the higher energy level on absorbing required amounts of energy or emit energy on moving from higher state to the lower state.

1. An orbital is having n = 3 and l = 1, the number of electrons it can occupy are

(a) 6

(b) 14

(c) 10

(d) 2

2. The force that allows electrons to move around the nucleus is

(a) nuclear force

(b) weak nuclear force

(c) electrostatic force

(d) gravitational force

3. According to Bohr’s atomic model, the radius of the orbit is directly proportional to

(a) n2

(b) 1/n2

(c) 1/n

(d) n

4. According to Bohr’s atomic model, the angular momentum of orbits is multiple of

(a) h/2𝜋

(b) 2𝜋/h

(c) 2h/𝜋

(d) 𝜋/2h

5. When electrons move from a lower energy level to a higher energy level, energy is

(a) absorbed

(b) emitted

(c) both (a) and (b)

(d) none of the above

6. Radius of the hydrogen atom on going to the first excited state is _____ of Bohr’s radius.

(a) double

(b) half

(c) 4 times

(d) same

7. The energy of each orbit is

(a) same

(b) fixed

(c) changes with time

(d) none of the above

8. How many atomic orbitals are present in the fourth energy level of an atom?

(a) 32

(b) 8

(c) 16

(d) 4

9. A subshell of an atom contains a maximum of _____ electrons.

(a) 4l – 2

(b) 4l + 2

(c) 2l + 1

(d) 2n2

10. When electrons move from the higher energy level to a lower energy level, energy is

(a) absorbed

(b) emitted

(c) both (a) and (b)

(d) none of the above