So, I have a general chemistry test. My teacher said to know...

"Copper and Chromium exceptions."

I have no idea what that means. I am currently learning about Thermochemistry and the Quantum Theory of an Atom.

Do you have any idea what this might mean??

Thank you for any thoughts!!

Yes.

The electron configuration of the 3d elements (Sc through Zn) is orderly EXCEPT for Cr and Cu.
21Sc 1s2 2s2 2p6 3s2 3p6 3d1 4s2
22Ti 1s2 2s2 2p6 3s2 3p6 3d2 4s2
23V 1s2 2s2 2p6 3s2 3p6 3d3 4s2
24Cr 1s2 2s2 2p6 3s2 3p6 3d5 4s1
25Mn 1s2 2s2 2p6 3s2 3p6 3d5 4s2
26Fe 1s2 2s2 2p6 3s2 3p6 3d6 4s2
27Co 1s2 2s2 2p6 3s2 3p6 3d7 4s2
28Ni 1s2 2s2 2p6 3s2 3p6 3d8 4s2
29Cu 1s2 2s2 2p6 3s2 3p6 3d10 4s1
30Zn 1s2 2s2 2p6 3s2 3p6 3d10 4s2

I have highlighted the Cr and Cu exceptions in the 3d orbital.