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

Answer(2) `n_1 =1, n_2 = 3`
energy given to hydrogen atom, .
`E = 13.6 (1/n_1^2 - 1/n_2^2)` .
= `13.6 (1/1 - 1/(3)^2)` .
= 12.08 eV .
`therefore E approx 12.1 eV`