#55 d

[Jade Fosburgh Discussion 2C]

For Cu, Ag, and Au, why is the electron configuration ns1(n-1)d^10? Instead of ns^2(n-1)d^9?

[Qining Jin 1F]

A full d^10 is more stable than d^9, so the electron configuration is ns^1(n-1)d^10

[Sue Xu 2K]

The orbitals are always the most stable when they are half filled or full, because of the electron repulsion force. So the electron will alway try to fill in the orbitals that way.

[Jennie Fox 1D]

A half filled D-orbital (d^5) or a filled D-orbital (d^10) is more stable than d^4 or d^9, for example, so the electron from the S-orbital will "jump" to the d-orbital in order to make it more stable. In this case, the electron will jump to the d-orbital in order to completely fill it (d^10).