G

Gallium

IUPAC: Gallium

Ga Elements CAS 7440-55-3
Quick Reference
Formula / NotationGa
CAS Number7440-55-3
Molecular Weight69.72
Melting Point29.8
Boiling Point2229.0
Density5.91
SolubilityInsoluble in water
AppearanceSoft, silvery metal; liquid just above room temperature
Also Known AsGa, gallium metal
CategoryElements

What is Gallium?

Gallium is a soft, silvery metal, atomic number 31. Famous for melting just above room temperature (29.8 C) - it melts in the palm of your hand. Gallium arsenide (GaAs) and gallium nitride (GaN) are key semiconductors for LEDs, lasers, and high-frequency electronics.

Formula & Notation

Ga

IUPAC Name: Gallium

Other Names / Synonyms: Ga, gallium metal

Properties & Characteristics

Atomic number: 31. Atomic mass: 69.723 g/mol. Period 4, Group 13. Melting point: 29.8 C. Boiling point: 2229 C. Density: 5.91 g/cm3 (liquid). Electronegativity: 1.81. Oxidation state: +3. Expands on solidification (like water). Two stable isotopes: Ga-69 (60.1%), Ga-71 (39.9%).

Physical Data

PropertyValue
Melting Point29.8
Boiling Point2229.0
Density5.91
Molecular Weight69.72
SolubilityInsoluble in water
AppearanceSoft, silvery metal; liquid just above room temperature

Uses & Applications

GaAs semiconductor (solar cells, high-speed electronics, microwave devices). GaN LEDs and laser diodes (blue LEDs - Nobel Prize 2014). High-temperature thermometers. Gallium alloys (low melting). Pharmaceuticals (Ga-67 imaging agent). MRI contrast agents.

Safety Information

Gallium metal: low acute toxicity. Skin contact with liquid gallium: mildly irritating. Gallium compounds: low to moderate toxicity. GaAs: potentially toxic (contains arsenic) - handle with care. Gallium alloys: may wet and corrode aluminium aircraft parts.

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

Key Facts

Term Gallium
Formula Ga
CAS Number 7440-55-3
Molecular Weight 69.72
Category Elements
Synonyms Ga, gallium metal

Frequently Asked Questions

Gallium is a soft, silvery metal, atomic number 31. Famous for melting just above room temperature (29.8 C) - it melts in the palm of your hand. Gallium arsenide (GaAs) and gallium nitride (GaN) are key semiconductors for LEDs, lasers, and high-frequency electronics.

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