Question

The CORRECT order of first ionisation enthalpy is : 

(1) Mg < S < Al < P 

(2) Mg < Al < S < P 

(3) Al < Mg < S < P 

(4) Mg < Al < P < S

Answer 1

Answer is : (3) Al < Mg < S < P

Mg Al P S → IE. order

Al< Mg < S < P

Answer 2

Correct option is (3) : Al < Mg < S < P 

Due to fully filled configuration of Mg it has high IE than Al and due to half filled configuration of P it has high IE than S