# What is the electron configuration of gold?

Jul 1, 2017

${\text{[Xe]" "4f"^14 "5d"^10 "6s}}^{1}$

#### Explanation:

As you can see, the nearest noble gas to gold without going over, is xenon (Xe). The reason '$\text{[Xe]}$' appears in the noble gas electronic configuration is because they both share the same electron configuration (although for good, its part of it).

Jul 1, 2017

With an atomic number of $79$, $\text{Au}$ has a configuration of...

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

and not $5 {d}^{9} 6 {s}^{2}$.

It has a xenon core, plus a $4 f$ outer core. Surprisingly enough, due to scalar relativistic effects (gold's $1 s$ electron moves at 57.7% the speed of light), its $6 s$ electron contracts and its $5 d$ and $4 f$ orbitals expand, so that despite having one valence electron, gold is not very reactive.