The incorrect statement Among the following is A)The first ionisation potential of Al is less than the first ionisation potential of Mg. B)The first ionisation potential of Na is less than the first ionisation potential of Mg. C)The second ionisation potential of Mg greater than the second ionisation potential of Na D)The third ionisation potential of Mg greater than the third ionisation potential of Al

Options

A. The first ionization potential of Al is less than the first ionization potential of Mg
B. The second ionization potential of Mg is greater than the second ionization potential of `Na^+`
C. The first ionization potential of Na is less than the first ionization potential of Mg
D. The third ionization potential of Mg is greater than that of Al

Answer

B

Explanation

`I.E._2` of Na is higher than that of Mg because in case in Na, the second `e^-` has to be removed from the noble gas core while in case of magnesium removal of second `e^-` electron gives a noble gas core. Mg has higher first ionization potential than Na because of its stable `ns^2` configuration.