Question

The ionization energy of a hydrogen atom is 13.6eV. The energy of the third-lowest electronic level in doubly ionized lithium (Z = 3) is -

Answer 1

ANSWER

Bohr's model is used to solve this question,

According to this E=−13.6×n2Z2 

So, in this the E is equal to energy of electron in nth shell of atom whose atomic number is Z

. 

Now, same amount of energy with opposite sign must be given to electron in order to remove it. I.E.=−13.6×Z2eV   (As n=1)

 Since for Lithium, Z=3 

Therefore, you get I.E.=−122.4eV