Mercury (element)
A heavy, silvery liquid metal with unique physical properties and high toxicity.
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and is the only metallic element that is liquid at standard temperature and pressure. Mercury occurs in deposits worldwide, mostly as cinnabar (mercuric sulfide), and has been used since ancient times in applications ranging from pigments to scientific instruments.
- symbol
- Hg
- atomic_number
- 80
- phase_at_STP
- liquid
- melting_point
- −38.83 °C
- density_at_STP
- 13.69 g/cm³ (liquid)
- known_for
- only metallic element liquid at standard temperature and pressure; toxic; used in thermometers and amalgams
Lore & Background
In China and Tibet, mercury was thought to prolong life and heal fractures, though exposure to mercury vapor is now known to cause serious health effects. The first emperor of a unified China, Qín Shǐ Huáng Dì, was reportedly killed by drinking a mercury and powdered jade mixture intended as an elixir of immortality. Mercury is the only metal for which the alchemical planetary name survives, derived from the planet Mercury. Its chemical symbol Hg comes from hydrargyrum, a Latinized form of the ancient Greek word for 'water-silver.' In medieval alchemy, quicksilver was associated with the fastest planet, named after the Roman god Mercury. It has seven stable isotopes, with 202Hg being the most abundant. Mercury dissolves many metals to form amalgams, and its toxicity has led to reduced use in instruments, though it remains in scientific research and some dental restorations.
Reader's Guide
Mercury is significant as the only metallic element that is liquid at standard temperature and pressure, with the lowest melting and boiling points of any stable metal. Its unique physical properties made it essential in thermometers, barometers, and other instruments for centuries. However, its toxicity to the nervous system, immune system, and kidneys has driven a reduction in its use, with many manufacturers eliminating it from products. Mercury still appears in fluorescent lighting, where electricity passed through mercury vapor produces ultraviolet light that causes phosphors to fluoresce. Its ability to form amalgams with metals like gold and silver has historical and industrial importance, though it can seriously corrode aluminum. Mercury's legacy is dual: a substance of great utility and scientific interest, but also a potent environmental and health hazard requiring careful handling.
Did You Know?
- Mercury is the only metallic element that is liquid at standard temperature and pressure.
- The chemical symbol Hg comes from hydrargyrum, a Latinized form of the ancient Greek word for 'water-silver.'
- Mercury reacts with solid sulfur flakes, which are used in mercury spill kits to absorb it.
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