In accordance with the Bohr’s model, find the quantum number that characterises the earth’s revolution around the sun in an orbit of radius 1.5 × 10¹¹ m with orbital speed 3 × 10⁴ m/s. (Mass of earth = 6.0 × 10²⁴ kg.)

Angular momentum is given by the relation:

⇒

Where M is the mass of Earth and is equal to 6.0 × 10²⁴ kg.

v is the orbital speed of Earth = 3 × 10⁴ m/s.

r is the orbital radius of Earth= 1.5 × 10¹¹ m

n is the quantum number

substituting the values, we get

on calculating, we get

n =2.6 × 10⁷⁴