Gold (Au)
Transition metal
Gold has been treasure for every civilisation: it never tarnishes, works easily, and gleams unmistakably. Beyond wealth, it bonds microchips, reflects infrared in astronaut visors and treats some medical conditions.
Position on the periodic table
Atomic properties
| Atomic number | 79 |
|---|---|
| Atomic mass | 196.967 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10 |
| Noble gas shorthand | [Xe] 4f14 5d10 6s1 |
| Electrons per shell | 2, 8, 18, 32, 18, 1 |
| Valence electrons (outer shell) | 1 |
| Common oxidation states | +3, +1 |
| Electronegativity (Pauling) | 2.54 |
| Covalent radius (approx.) | 136 pm |
| First ionization energy | 890.1 kJ/mol |
| Electron affinity | 222.7 kJ/mol |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 19.3 g/cm³ |
| Melting point | 1064.2 °C (1337.3 K) |
| Boiling point | 2969.8 °C (3243 K) |
| Appearance | metallic yellow |
| Radioactive | No |
| Origin | Occurs naturally |
Electron configuration of gold
Gold's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10, usually shortened to [Xe] 4f14 5d10 6s1. Its electrons occupy 6 shells (2, 8, 18, 32, 18, 1), placing it in period 6 of the d-block. Explore it interactively in the electron configuration calculator.
Uses of gold
- Jewellery and investment
- Electronics (corrosion-proof connectors and bond wires)
- Astronaut visors and satellite insulation
- Dentistry and some medicines
Biological role: None known.
Occurrence: Found native in veins and river gravels; seawater holds vast but unrecoverable traces.
Common compounds of gold
AuCl3
Gold(III) chloride
History and discovery
Discovered: Known since ancient times — Middle East. Name origin: From Old English gold; the symbol Au is from Latin aurum, “shining dawn”.
Worked since at least 4000 BCE; the quest to make gold drove alchemy and, eventually, real chemistry.
Safety notes
Metallic gold is completely inert — safe enough to eat as decorative leaf.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Gold
1. What is the chemical symbol of Gold?
2. What is the atomic number of Gold?
3. Which category does Gold belong to?
4. What is the state of Gold at room temperature?
5. Which period of the periodic table is Gold in?
Gold FAQs
What is the atomic number of gold?
Gold's atomic number is 79 — every gold atom has 79 protons in its nucleus.
What is the symbol for gold?
Au. From Old English gold; the symbol Au is from Latin aurum, “shining dawn”.
Is gold a metal, nonmetal, or metalloid?
Gold is classified as a transition metal.
What state is gold at room temperature?
At about 25 °C, gold is a solid. It melts at 1064.2 °C.
What is gold used for?
Key uses include: jewellery and investment; electronics (corrosion-proof connectors and bond wires); astronaut visors and satellite insulation.
Related elements
Keep working with this element
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