Question

Which of the following element has 2nd IP < 1st IP
(1) Mg
(2) Ne
(3) C
(4) None​

Answer 1

Answer:

Magnesium has fully filled s orbital and thus first ionization potential is higher . Thus, first ionization potential will be higher. After loss of one electron, the second electron will be lost easily as it will acquire inert gas configuration after loss of second electron. Thus 2nd IP < 1st IP for magnesium.