Mercury has the lowest melting point among metals that are liquid near room temperature.
Mercury melts at about −38.83 °C, so it remains liquid in ordinary indoor conditions. It is the only metallic element that is liquid at standard room temperature, although gallium, cesium, and rubidium can melt close to or slightly above it under suitable conditions.
Its chemical symbol is Hg, derived from the Greek and Latin traditions associated with hydrargyrum, meaning “watery silver.” Mercury has atomic number 80 and is a dense, silvery metal that forms spherical droplets because of its surface tension.
Thermometers, barometers, switches, lamps, and dental amalgam historically used mercury. Because mercury and many of its compounds are toxic, numerous uses have been restricted or replaced. Bromine is also liquid at room temperature, but it is a halogen and not a metal.