Gold (Au)

Yellowish-white metal

Gold is the eternal metal—found in ancient tombs, central banks, and every circuit board, and with [Xe] 4f¹⁴ 5d¹⁰ 6s¹, relativistic effects contract the 6s orbital, giving gold its distinctive yellow color (the only colored coinage metal). Gold nanoparticles are used in rapid diagnostic tests and cancer therapy.

Key metrics

Density19.32g/cm³

Melting point1,337K

Boiling point3,129K

Electronegativity2.54Pauling

Discovery

-6000discovered

Discovered by: Ancient civilizations
Reactivity profile: Highly unreactive
Reactivity: Low
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Xe]}\; \textcolor{#a855f7}{4_{f}^{14}}\; \textcolor{#22c55e}{5_{d}^{10}}\; \textcolor{#ef4444}{6_{s}^{1}}

[Xe] 4f14 5d10 6s1

Wave function

\Psi_{\text{Au}} \approx \frac{1}{\sqrt{79!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{79}(\mathbf{r}_{79}) \right|

Probability density $|\Psi|^2$ across the Au valence shell.

Crystal structure

Face-Centered Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number12

Atoms per cell4

Atomic packing factor0.74

Physical properties

Atomic radius: 144 pm
Ionization energy: 890 kJ/mol
Electron affinity: 223 kJ/mol
Crystal structure: Face-centered cubic (fcc)

Oxidation states

+1+3

Acid/base

Neutral

Strongly acidicStrongly basic

State at 25 °CSolid

1337 K3129 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

442.5nmAu IViolet70%

479.3nmAu I (blue)Blue100%

525.6nmAu I (green)Green50%

Dominant line 479.3 nmRange 443–526 nmTransitions 3