1.Previous
3.Next

valence electrons ranges from 3 to 12 (ns and (n-1)d orbitals).
*For lanthanides and actinides, the number of valence electrons ranges from 3 to 16 (ns, (n-2)f and (n-1)d orbitals).

All other non-valence electrons for an atom of that element are considered core electrons.

Orbital theory

A more complex explanation of the difference between core and valence electrons can be described with atomic orbital theory.

1.Previous
3.Next