Account for the variation in metallic or non-metallic character in third row elements.

Name the element having general electronic configuration ${\mathrm{ns}}^2{\mathrm{np}}^4$ in fourth period.

Consider the ground state electronic Configuration given below.
(A) $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6$
(B) $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$