Why is the electronic configuration for Chromium unusual?

Answer 1

The electron configuration is unusual because electrons prefer to be paired or alone in a subshell. Since Chromium has 4 valence e-, one of the paired electrons of the 4s2 subshell moves into the 3d subshell, thus giving 5 unpaired e- in the 3d subshell, and one in the 4s subshell. A similar concept applies to copper, just that in that case the e- from the 4s subshell makes 5 pairs of e- in the 3d subshell.

Answer 2

the electronic configuration for Chromium is [Ar]4s1 3d5. because its atomic no. is 24

Answer 3

[Ar]3d^5 4s^2