Mercury is a chemical element; it has symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum from the Greek words hydor and argyros. Symbol: Hg Atomic number: 80 Melting point: -37.89�°F (-38.83�°C) Atomic mass: 200.59 u Boiling point: 674.1 F (356.7 C) Electron configuration: [Xe] 4f 5d 6s Density: 13.546 g/cm3