The effective nuclear charge, Z eff , for a valence electron can be approximated using the core charge of the atom; that is, the total charge of the nucleus and the inner (nonvalence) electrons.

Question

Determine the core charge for an atom of Si

Answer 1

So, Si has 14 protons and an electron configuration of 1s2 2s2 2p6 3s2 3p2

The Zeff is approximated as #protons - core electrons = 14 - 10 = 4 as the effective nuclear charge