Ga

Gallium (symbol Ga, atomic number 31) is a chemical element in group 13 of the periodic table. It is a soft, silvery-blue metal with a very low melting point of 29.76 °C, so it can melt in a warm hand. At room temperature it remains solid but becomes malleable as it approaches its melting point. It expands slightly upon solidification and has a high boiling point of about 2,204 °C. It forms a thin protective oxide layer when exposed to air.

Occurrence and production: Gallium is not found free in nature and occurs only in trace amounts in minerals. It is most commonly recovered as a byproduct of refining zinc ores and from bauxite during aluminum production. Global production is concentrated in a few countries and results largely from byproduct processing rather than direct mining. Purified gallium metal is produced by reducing Ga-containing oxides and then purified, often by electrolysis.

Isotopes and history: Naturally occurring gallium consists of two stable isotopes, 69Ga and 71Ga. In 1875, French chemist Paul-Émile Lecoq de Boisbaudran identified gallium by spectroscopy and named it after Gallia, the Latin name for France.

Applications: Gallium is essential in electronics and optoelectronics. Gallium arsenide (GaAs) and gallium nitride (GaN) are key semiconductors used in LEDs, lasers, high-speed electronics, and solar cells. Liquid alloys such as Galinstan (gallium–indium–tin) are liquid at room temperature and provide non-toxic alternatives to mercury in some applications. Gallium isotopes such as Ga-67 and Ga-68 are used in medical imaging and radiopharmaceuticals.

Safety: Gallium metal is considered of low toxicity; certain gallium compounds can be hazardous and should be handled with proper precautions.