Question

Predict the ground-state electron configuration of the following ions Ru^2+

Answer 1

[Kr]4d\(^6\)

Answer 2

If you need the complete electron configuration for the ATOM:
\[1s ^{2}2s ^{2}2p ^{6}3s ^{2}3p ^{6}4s ^{2}3d ^{10}4p ^{6}5s ^{2}4d ^{6}\]
But, because you have an ion, the atom will lose electrons from its highest energy level first, which is
\[5s ^{2}\]
Losing the 2 electrons from this level causes the ion to be
\[Ru ^{2+}\]
and the new complete electron configuration becomes:
\[1s ^{2}2s ^{2}2p ^{6}3s ^{2}3p ^{6}4s ^{2}3d ^{10}4p ^{6}4d ^{6}\]