G

Gold

IUPAC: Gold

Au Elements CAS 7440-57-5
Quick Reference
Formula / NotationAu
CAS Number7440-57-5
Molecular Weight196.97
Melting Point1064.0
Boiling Point2856.0
Density19.3
SolubilityInsoluble in water
AppearanceBright, dense, soft, yellow-coloured metal
Also Known AsAu, aurum, gold metal
CategoryElements

What is Gold?

Gold is a bright, dense, malleable precious metal, atomic number 79. The most malleable and ductile pure metal. Chemically unreactive - resists corrosion and oxidation. Used as currency, jewellery, and in electronics. Colloidal gold nanoparticles are red/purple.

Formula & Notation

Au

IUPAC Name: Gold

Other Names / Synonyms: Au, aurum, gold metal

Properties & Characteristics

Atomic number: 79. Atomic mass: 196.97 g/mol. Period 6, Group 11. Melting point: 1064 C. Boiling point: 2856 C. Density: 19.30 g/cm3. Electronegativity: 2.54. Oxidation states: +1, +3. One stable isotope: Au-197. Most malleable metal (1 gram -> 1 m2 foil).

Physical Data

PropertyValue
Melting Point1064.0
Boiling Point2856.0
Density19.3
Molecular Weight196.97
SolubilityInsoluble in water
AppearanceBright, dense, soft, yellow-coloured metal

Uses & Applications

Jewellery and currency (largest uses). Electronics (gold contacts and connectors - corrosion resistant). Gold nanoparticles for medical diagnostics and drug delivery. Dental alloys. Gold leaf decoration. Gold-198 (Au-198) cancer therapy. Colloidal gold in pregnancy tests.

Safety Information

Gold metal: essentially non-toxic (used in food as E175). Gold compounds: moderate toxicity - sodium aurothiomalate causes side effects in rheumatoid arthritis treatment. Chloroauric acid: corrosive. Gold cyanide process: highly toxic cyanide compounds used in mining.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Gold
Formula Au
CAS Number 7440-57-5
Molecular Weight 196.97
Category Elements
Synonyms Au, aurum, gold metal

Frequently Asked Questions

Gold is a bright, dense, malleable precious metal, atomic number 79. The most malleable and ductile pure metal. Chemically unreactive - resists corrosion and oxidation. Used as currency, jewellery, and in electronics. Colloidal gold nanoparticles are red/purple.

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