The name “gallium” derives from Gallia, the Latin name for France, in honor of its discoverer’s homeland.

Before its discovery, gallium was predicted by Dmitri Mendeleev (who called it “eka-aluminium”) based on a gap he noticed in his periodic table.

Gallium’s chemical symbol is Ga, and its atomic number is 31. It belongs to Group 13 (the boron group) of the periodic table. The atomic weight of gallium is approximately 69.723 u.

Its melting point is about 29.76 °C (85.57 °F), meaning it can melt in your hand. The boiling point is around 2204 °C (≈3999 °F), giving it an unusually large liquid range for a metal.

In its solid state at room temperature, gallium is a soft, bluish-gray or silvery metal that can be easily cut with a knife.

People sometimes handle gallium with gloves not because it is highly toxic (it isn’t), but because it tends to stain the skin and is difficult to wash off.

Gallium expands when it freezes (by about 3%), which is uncommon for a metal.

It was discovered in 1875 by Paul Émile Lecoq de Boisbaudran, a French chemist.

Gallium does not occur naturally in its free elemental state; it is found only in trace amounts, such as in bauxite and zinc ores.

The abundance of gallium in Earth’s crust is roughly 19 parts per million (ppm) by weight, making it the 34th most abundant element.

A major use of gallium is in semiconductors, particularly in compounds such as gallium arsenide (GaAs) and gallium nitride (GaN), which are essential in LEDs, laser diodes, and other electronic devices.

It adheres to glass and porcelain surfaces and can form brilliant mirror-like coatings.

Gallium is used in high-temperature thermometers and barometers, thanks to its wide liquid range.

Gallium oxide and its compounds are used in LEDs and solar cells. For example, GaN is critical in blue and green LED technology.

Although gallium is relatively abundant compared to some so-called rare metals, it seldom forms deposits concentrated enough to be mined directly; instead, it is primarily recovered as a by-product of processing other ores.

Gallium’s melting point of approximately 29.76 °C serves as a reference point in the International Temperature Scale (ITS-90).

A small amount of gallium exists in the human body (around 0.7 mg in a 70 kg person) though it has no known biological function.