(A) The electronic configurations of Nitrogen $(N)$ and Phosphorus $(P)$ are as follows:
| Element | Electronic Configuration $(K, L, M)$ |
| Nitrogen $(Z=7)$ | $2, 5$ |
| Phosphorus $(Z=15)$ | $2, 8, 5$ |
Nitrogen is more electronegative than phosphorus.
Reasoning:
$1$. Electronegativity is the tendency of an atom to attract a shared pair of electrons towards itself.
$2$. As we move down a group in the Periodic Table,the number of electron shells increases.
$3$. In Nitrogen,the valence electrons are in the $L$ shell (closer to the nucleus),whereas in Phosphorus,they are in the $M$ shell (further from the nucleus).
$4$. Due to the increased distance from the nucleus and increased shielding effect,the effective nuclear charge experienced by the valence electrons decreases as we move down the group.
$5$. Consequently,the ability to attract electrons decreases,making Nitrogen more electronegative than Phosphorus.