The ground state energy of hydrogen atom is - 13.6 eV. When electron is in excited state its excitation energy is ......

Options

A. `3.4eV`
B. `6.8eV`
C. `10.2eV`
D. 0

Answer

C

Explanation

When the electron is in the first excited state (n = 2) then its energy,,

`DeltaE=E_(2)-E_(1) "also" E_(n)=-(13.6)/(n^(2))eV`
`:.Delta=-(13.6)/(2^(2))-((13.6)/(1^(2)))`
`=-3.4+13.6`
`:.DeltaE=(-3.4)-(-13.6)=10.2eV`