Gallium
Definition and meaning of Gallium in chemistry.
Gallium is a soft, silvery post-transition metal identified by the chemical symbol Ga and atomic number 31. It is notable for having a melting point so low that the solid metal can literally melt into a liquid when held in the palm of a human hand.
In more detail
Located in group 13 of the periodic table, gallium does not occur in nature as a free uncombined element but is typically extracted in trace amounts as a valuable byproduct from the processing of bauxite and zinc ores. The highly pure solid metal fractures conchoidally much like glass, yet it expands by over three percent when freezing from its liquid state, an anomalous and rare structural property shared only with water, silicon, and a few other substances. It forms chemical compounds primarily in the +3 oxidation state and bonds covalently in many of its solid crystalline phases, though +1 state compounds have also been observed under specific laboratory conditions. Gallium is renowned among metallurgists for easily forming alloys with most other metals, significantly reducing the melting points of those resulting alloys to create specialized liquid metal coolants. Its unique semiconductor characteristics have made it indispensable in modern microelectronics, particularly in the mass production of optoelectronic devices, light-emitting diodes, and high-frequency integrated circuits.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Ga |
| Atomic number | 31 |
| Atomic mass | 69.723 u |
| Category | Post Transition Metal |
| State at room temperature | Solid (melts slightly above ambient) |
| Melting point | 29.76 °C (85.58 °F) |
| Boiling point | 2204 °C (3999 °F) |
Gallium arsenide is a vital semiconductor material utilized heavily in manufacturing high-efficiency light-emitting diodes and microwave frequency integrated circuits.
Frequently asked questions
Why does gallium melt in your hand?
Its melting point of 29.76 degrees Celsius is just below standard human body temperature, transferring enough thermal energy from human skin to trigger a phase change.
What happens when gallium contacts aluminum?
Liquid gallium rapidly permeates the grain boundaries of solid aluminum, completely destroying its structural integrity and causing the aluminum metal to become extremely brittle.