question_answer

The binding energy of the electron in a hydrogen atom is13.6 eV, the energy required to remove the electron from the first excited state of \[\text{L}{{\text{i}}^{\text{++}}}\] is:              [JEE ONLINE 09-04-2014]

A) 122.4 eV

B) 30.6 eV

C) 13.6 eV

D) 3.4 eV

Correct Answer: B

Solution :

[b] For first excited state, n = 2 and for