Question

The first ionization energies of alkaline earth metals are higher than those of the alkali metals. This is because:

• A. there is increase in the nuclear charge of the alkaline earth metals
• B. there is decrease in the nuclear charge of the alkaline earth metals
• C. there is no change in the nuclear charge
• D. none of the above

Answer 1

The correct option is A

there is increase in the nuclear charge of the alkaline earth metals

General electronic configuration for alkali metals is $n{s}^1$ and alkaline earth metals are $n{s}^2$ . Due to completely filled s-orbital, alkaline earth metals have a higher I.P than Alkali metals.