An electron colliodes with a hydrogen atom in its ground state and excites it to n=3 state . The energy given to the hydrogen atom in this inelastic collision
( neglecting the recoil of hydrogen atom ) is

Options

A. `10.2eV`
B. `12.1eV`
C. `12.5eV`
D. `13.6eV`

Answer

B

Explanation

According to the question ,
energy given to hydrogen atom = Difference in energy level `n_1 ` to ` n_2 = 3 ` states
`= 13.6 ((1)/(n_1^2 )-(1)/(n _2^2))= 13.6 ((1)/(1^2 ) - (1)/(3^2))=13.6 (1-1/9)`
`13.6 xx (8) /(9) = 12.08 ~~ 12.1 eV `