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

Options

A. There is increase in the nuclear charge of the alkaline earth mtal
B. There is decrease in the nuclear charge of the alkaline earth metal
C. Ther is no change in the nuclear charge
D. None of these

Answer

A

Explanation

Along the period from left to right, atomic increases and therfore nuclear charge also increases first ionization energ of alkaline earth metals are helps than those of the alkali metals of the same period because of higher nuclear charge.