Question

How do you write the electron configuration of scandium?

Answer 1

`Sc, Z=21`

Explanation:

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^1`

We account for 21 electrons. The valence orbitals may have different ordering (i.e. `3d^(1)4s^2`) but this really doesn't matter so much. Scandium metal commonly forms `Sc^(3+)` ions.