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80 Hg 200.59(2)

Mercury

Transition metal
Symbol Hg
Atomic Number 80
Atomic Weight 200.59(2)
CAS Registry ID 7439-97-6
Group Name (none)
Period Number 6
Block d-block
State at STP Solid

Description

Sample of Mercury ⌕ Enlarge Image

Mercury is a transition metal that is a bright silver color in its natural liquid state. It is one of the few metals that is a liquid at room temperatures and pressure. Mercury has an atomic weight of 200.59, a melting point of - 37.89 °F, and a boiling point of 674.11 °F. Mercury is most often used in scientific thermometers; it is also used in barometers, diffusion pumps, sphygmomanometers, electron tubes, neon signs, dentistry amalgams, and in the production of atomic clocks.

Isolation

Mercury occurs in nature in its native form in nature, but it is extremely rare. More often, mercury is isolated from minerals in which it occurs in.

Mercury ⌕ Enlarge Image

The process of isolating mercury used to be carried out for science demonstrations in small laboratories, but the high toxicity of mercury compounds that was realized over the years has put a stop to anything but commercial mercury isolation. Most mercury extractions and isolations for commercial uses are from the mineral cinnabar; this mineral contains high amounts of mercury sulfide. Other minerals which contain mercury include corderoite and livinstonite.

The isolation process of mercury from cinnabar is relatively simple. The cinnabar is heated to approximately 1112 °F and a current of air is run through the heated mineral. Oxygen from the air reacts with the sulfur in the cinnabar to produce pure mercury liquid and gaseous sulfuric oxide. This liquid mercury is washed with nitric acid and exposed again to air treatments to remove any impurities that remained; distilling the liquid at reduced pressure will result in a highly pure isolated form of liquid mercury metal.

General

NameMercury
SymbolHg
Number80
Chemical seriesTransition metal
Group12
Period6
Blockd
Appearancesilvery
Standard atomic weight200.59(2) g·mol⁻¹
Electron configuration[Xe] 4f14 5d10 6s2
Electrons per shell2, 8, 18, 32, 18, 2

Atomic Properties

Crystal structurerhombohedral
Oxidation states2 (mercuric), 1 (mercurous) (mildly basic oxide)
Electronegativity2.00 (scale Pauling)
Ionization energies1st: 1007.1 kJ/mol
2nd: 1810 kJ/mol
3rd: 3300 kJ/mol
Atomic radius150 pm
Atomic radius (calc.)171 pm
Covalent radius149 pm
Van der Waals radius155 pm

Physical Properties

Phaseliquid
Density (near r.t.)(liquid) 13.534  g·cm−3
Liquid density at m.p.
Melting point234.32 K (-38.83 °C, -37.89 °F)
Boiling point629.88 K (356.73 °C, 674.11 °F)
Critical point1750 K, 172.00 MPa
Heat of fusion2.29  kJ·mol−1
Heat of vaporization59.11  kJ·mol−1
Heat capacity(25 °C) 27.983  J·mol−1·K−1

Miscellaneous

Magnetic orderingdiamagnetic
Electrical resistivity(25 °C) 961 nΩ·m
Thermal conductivity(300 K) 8.30  W·m−1·K−1
Thermal expansion(25 °C) 60.4  µm·m−1·K−1
Speed of sound (thin rod)(liquid, 20 °C) 1451.4 m/s
Young's modulus
Shear modulus
Bulk modulus
Poisson ratio
Mohs hardness
Vickers hardness
Brinell hardness