Gallium is a silver-white metal. The density is 5.904 g/cm3. The melting point is 29.78°C. The boiling point is 2403°C. Due to the complex structure of stable solids, pure liquids have a significant tendency to overcool and can be kept in an ice bath for several days without crystallization. It is soft, brittle, and stable in the air. It is soluble in acid and alkali when heated; it reacts violently with boiling water, but only slightly reacts with water at room temperature. It can interact with most metals at high temperatures. When it is converted from liquid to solid, the expansion rate is 3.1%, and it is suitable to be stored in a plastic container. It swells when it solidifies, and is usually obtained as a by-product of extracting aluminum from bauxite or zinc from zinc ore, or it is often dispersed in small amounts in aluminum ore, sphalerite and other ores in nature. Extracted from bauxite.