Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum.

Mercury is the only metal that is a liquid at standard temperature and pressure. The only other liquid element under standard conditions is bromine (a halogen), although the metals rubidium, cesium, and gallium melt at a temperature just above room temperature. … Mercury is a very rare element in the Earth’s crust.