Mercury is a metal element denoted by the atomic symbol Hg. It has an atomic number of 80 and an atomic weight of 200.59. Mercury, unlike any other metal, is liquid at room temperature. When poured onto a smooth surface, it forms beads that roll rapidly around, getting larger or smaller as they collide.

No one knows exactly when mercury was discovered, but many ancient civilizations were familiar with this metallic element. As long ago as Roman times, people had learned to extract mercury from its ore and use it to purify gold and silver. The ancient name for mercury was quicksilver, meaning "living" silver. This name reflected mercury's lustrous silver color and its unusually lively behavior. The element's modern name came from Mercury (or Mercurius), the fleet-footed messenger of the gods in Roman mythology. Its atomic symbol Hg comes from the word hydragyrum which means liquid silver...