Mercury

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum (/haɪˈdrɑːrdʒərəm/ hy-DRAR-jər-əm) from the Greek words hydro (water) and argyros (silver). A heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.

Mercury, ₈₀Hg

Mercury
Appearance	shiny, silvery liquid
Standard atomic weight Ar°(Hg)
	200.592±0.003 200.59±0.01 (abridged)
Mercury in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Cd ↑ Hg ↓ Cn gold ← mercury → thallium
Atomic number (Z)	80
Group	group 12
Period	period 6
Block	d-block
Electron configuration	[Xe] 4f14 5d10 6s2
Electrons per shell	2, 8, 18, 32, 18, 2
Physical properties
Phase at STP	liquid
Melting point	234.3210 K ​(−38.8290 °C, ​−37.8922 °F)
Boiling point	629.88 K ​(356.73 °C, ​674.11 °F)
Density (near r.t.)	13.546 g/cm3
Triple point	234.3156 K, ​1.65×10−7 kPa
Critical point	1750 K, 172.00 MPa
Heat of fusion	2.29 kJ/mol
Heat of vaporization	59.11 kJ/mol
Molar heat capacity	27.983 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 315 350 393 449 523 629
Atomic properties
Oxidation states	−2 , +1, +2 (a mildly basic oxide)
Electronegativity	Pauling scale: 2.00
Ionization energies	1st: 1007.1 kJ/mol 2nd: 1810 kJ/mol 3rd: 3300 kJ/mol
Atomic radius	empirical: 151 pm
Covalent radius	132±5 pm
Van der Waals radius	155 pm
Spectral lines of mercury
Other properties
Natural occurrence	primordial
Crystal structure	​rhombohedral
Speed of sound	liquid: 1451.4 m/s (at 20 °C)
Thermal expansion	60.4 µm/(m⋅K) (at 25 °C)
Thermal conductivity	8.30 W/(m⋅K)
Electrical resistivity	961 nΩ⋅m (at 25 °C)
Magnetic ordering	diamagnetic
Molar magnetic susceptibility	−33.44×10−6 cm3/mol (293 K)
CAS Number	7439-97-6
History
Discovery	Ancient Egyptians (before 1500 BCE)
Symbol	"Hg": from its Latin name hydrargyrum, itself from Greek hydrárgyros, 'water-silver'
Isotopes of mercury v e
Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 194Hg synth 444 y ε 194Au 195Hg synth 9.9 h ε 195Au 196Hg 0.15% stable 197Hg synth 64.14 h ε 197Au 198Hg 10.0% stable 199Hg 16.9% stable 200Hg 23.1% stable 201Hg 13.2% stable 202Hg 29.7% stable 203Hg synth 46.612 d β− 203Tl 204Hg 6.82% stable
Category: Mercury (element) view talk edit | references

Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide.

Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers. The mercury cell process (chlor-alkali) is used to produce chlorine and sodium or potassium hydroxide, but is phased out.

Mercury, and mercury compounds, remain in use in scientific research applications and in amalgam for dental restoration in some locales, and in some food manufacturing operations. In food manufacturing, mercuric chloride is used in the starch extraction process during rice, corn, and wheat refining to inhibit starch degrading enzymes. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent lamp produces short-wave ultraviolet light, which then causes the phosphor in the tube to fluoresce, making visible light.

Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), by inhalation of mercury vapor, or by ingesting any form of mercury. In serious form, it is also known as Minamata disease. Mercury poisoning is intensified with lead co-exposures.