How do you write the noble-gas electron configuration for gold?

Jul 6, 2017

You are correct, except it is an anomalous configuration (which most professors don't expect you to know entirely)!

Explanation:

$A u$: $\left[X e\right] 6 {s}^{2} 4 {f}^{14} 5 {d}^{9}$

is the expected configuration, however

$A u$: $\left[X e\right] 6 {s}^{1} 4 {f}^{14} 5 {d}^{10}$

is a more stable configuration that gold usually takes.

A full 5d subshell and a half full 6s subshell is preferable to the awkward "expected" configuration.