The first ionization energy of Ar is less than that of Ne. An explanation of this fact is that :

Options

A. The effective nuclear charge experienced by a valence electron in Ar is much larger than that in Ne
B. The effective nuclear charge experienced by a valence electron in Ar is much smaller than that in Ne
C. The atomic radius of Ar is larger than that of Ne
D. The atomic radius of Ar is smaller than that of Ne

Answer

B

Explanation

Down the group, as Zeff decreases