Question

What are the anomalous properties of 2nd period elements?

Answer 1

Anomalous Periodic Properties of Second Period Elements

Small size of these atoms.

High electronegativity.

Large charge/radius ratio.

These elements also have only 4 valence orbitals available (2s and 2p) for bonding as compared to the 9 available (3s, 3p, and 3d) to the other members of the respective groups, so their maximum covalency is 4.