Relativistic effects and the chemistry of gold

In atoms of high nuclear charge (Z), as a consequence of a relativistic effect, the s electrons of an atom become more bound and their orbitals smaller than if this effect were absent. Simultaneously, the d (and f ) electrons are less bound because of this effect, which scales roughly as Z2. Gold exhibits a large relativistic effect. This accounts for gold being more resistant to oxidation than silver. It also accounts for higher oxidation states being more accessible in gold than in silver. These effects are illustrated by some fluorine chemistry of gold and silver.