Electronic configuration of $\mathrm{Y}-1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$ In order to get octet configuration the element ‘Y’ must gain two electrons from other atoms.

$\mathrm{Y}+2{\mathrm{e}}^{-}\to \mathrm{Octet} \mathrm{configuration}\left({\mathrm{ns}}^2{\mathrm{np}}^6\right)$