Live relationshipv=Zecorev = Z - e_{core}
Atom builder. Valence electrons at 13 e⁻. Core + valence 22.88 e⁻, Total electrons 17 e⁻. Currently core + valence is over by 5.88 e⁻.ATOM BUILDERTUNINGNUCLEUS13 E⁻

Core + valence

22.88e⁻

Total electrons

17e⁻

13 e⁻

Atom builder. Valence electrons at 13 e⁻. Core + valence 22.88 e⁻, Total electrons 17 e⁻. Currently core + valence is over by 5.88 e⁻.

Narrative feed

You arrive at a materials lab predicting how a salt will bond.

The sample is chlorine: 17 electrons total, 10 locked in inner shells. The outer-shell count is wrong and the bonding prediction fails.