Electronic configuration of the group IV A elements

Carbon (C) $z=6$ $1s^{2}2s^{2}2p^{2}$
Silicon (Si) $z=14$ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{2}$
Germanium (Ge) $z=32$ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{2}$
Tin (Sn) $z=50$ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{2}$


In all these cases the outermost $p$-shell contains only 2 electrons.

Note: Due to accidental degeneracy the energy depends only on the principal quantum number in the simplest picture (e.g. the $s$ and $p$ states belonging to the same shell have the same energy). However, due to effects like LS coupling, this degeneracy may be lifted and the subshells may have slightly different energies (which is generally the case).


Stirling Engine 2020-01-02