Question

According to Bohr’s theory, the minimum energy required to remove an electron from the ground state of doubly ionized Li atom (Z = 3) is 

(1) 1.51 

(2) 13.6 

(3) 40.8

(4) 122.4

Answer 1

Correct option : (4) 122.4

Explanation : 

According to Bohr’s theory for hydrogen and hydrogen like atoms, the energy in electron volts is given by the relation.

For doubly ionised L_i atom z = 3 and it will behave like a hydrogen atom. For ground state. n = 1 and hence we have