Question

If the binding energy of electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron form the first state of Li²⁺ is.

(A) 13.6 eV 

(B) 30.6 eV 

(C) 122.4 eV 

(D) 3.4 eV

Answer 1

The correct option is (B) 30.6 eV.

Explanation:

Binding energy = [(13.6z²) / n²]

For Li²⁺, z = 3

∴ binding energy = [(13.6 × 9) / n²]

∴ Energy to remove from first state,

n = 2 is given by Energy = [(13.6 × 9) / 4] = 30.6 eV