Question

A photon beam of energy 12.1eV is incident on a hydrogen atom. The orbit to which electron of H-atom be excited is (a) 2nd (b) 3rd (c) 4th (d) 5th

Answer 1

Answer:

(b) 3rd

Explanation:

The emission of photon of 12.1eV shall correspond to the transition from n = 3 to n =1.

Thus,

ΔE = -13.6/n²f - n²1

= - 13.6/n² - (-13.6)/1²

= 12.1 + (- 13.6)

n² = -13.6/ - 1.5

n² = 9

n = 3

Therefore, the orbit to which electron of H-atom be excited is 3rd.