Previous Year NEET Question- Bohr Model Of Atom

• 2018: The radius of the first Bohr orbit of the hydrogen atom is 0.53 Å. The radius of the third Bohr orbit of the hydrogen atom will be

A) 1.59 Å B) 4.77 Å C) 9.54 Å D) 3.18 Å

Answer: B

Explanation:

The radius of the nth Bohr orbit of the hydrogen atom is given by

r = n^2 a_0

where

• r is the radius of the orbit in angstroms
• n is the principal quantum number
• a_0 is the Bohr radius, which is equal to 0.53 Å

In this problem, we are given that the radius of the first Bohr orbit is 0.53 Å. We are asked to find the radius of the third Bohr orbit. Substituting n = 3 into the equation for the radius of the nth Bohr orbit, we get

r = 3^2 a_0 = 9 a_0 = 4.77 Å