Question

The Bohr orbit radius for the hydrogen atom (n = 1) is approximately 0.53 . The radius for the first excited state (n = 2) orbit (in ) is :

(a) 0.13

(b) 1.06

(c) 4.77

(d) 2.12

Answer 1

Correct option (d) 2.12

Explanation:

Radius of nth orbit of H-atom rn = a0 × n2

where a0 = Bohr radius, radius of 1st orbit = 0.53

Now, for the radius of first excited state,