Question

If $X$ and $Y$ are the second ionisation potentials of alkali and alkaline earth metals of same period, then :

• A. $X>Y$
• B. $X<Y$
• C. $X=Y$
• D. $X<<Y$

Answer 1

Answer: (A)

$X>Y$

The general electronic configuration of Alkali metal is $n{s}^1$ so if we remove first electron(first ionization energy) it will become octet configuration,so to remove next electron it requires more energy(second ionization energy) ,whereas the general electronic configuration of alkali earth metals is $n{s}^2$ so the electrons can be lost easily.,so the second ionization energy of alkali metal is more than the alkali earth metal,so the order of ionization energy is $X>Y$.
Hence option A is correct.