079Transition metal · Group 11 · Period 6

Gold

Gold (Au) is element 79, a transition metal in the d-block — group 11, period 6. It is a solid at room temperature with 6 electron shells (2, 8, 18, 32, 18, 1) and an atomic mass of 196.9665695 u.

Atomic mass: 197.0 u
Phase · STP: solid
Melting: 1337 K · 1064 °C
Boiling: 3243 K · 2970 °C
Electronegativity: 2.54
Density: 19.3 g/cm³

Photograph — Hi-Res Images ofChemical Elements, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/gold.php

Identity

Atomic number: 79
Standard atomic weight: 197.0 u
Category: Transition metal
Group: 11
Period: 6
Block: d-block
Oxidation states: +3, +1

Physical properties

Melting point: 1337 K · 1064 °C
Boiling point: 3243 K · 2970 °C
Density: 19.3 g/cm³
Molar heat capacity: 25.418 J/(mol·K)
Atomic radius: 166 pm
Electron affinity: 222.747 kJ/mol

Atomic structure

79protons

118neutrons

79electrons

1valence e⁻

Noble-gas notation: [Xe] 4f14 5d10 6s1
Full configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10
Electrons per shell: 2, 8, 18, 32, 18, 1

Periodic trends

Where Gold ranks across all 118 elements.

Electronegativity2.54

Ionization energy890.1 kJ/mol

Electron affinity222.747 kJ/mol

Density19.3 g/cm³

Atomic radius166 pm

Ionization energies

Energy to remove each successive electron (kJ/mol).

890.1

2.0k

Successive ionization energies (kJ/mol, log scale).

Discovery

Discovered: Ancient
Discovered by: Middle East
Named by: —
Appearance: metallic yellow