Mercury is the only metal that is liquid at standard temperature and pressure, a property that results from a unique electron configuration that gives rise to unusually weak metallic bonds. Its chemical symbol Hg arises from the latin hydragyrum, meaning “liquid-silver”, and its common name was borrowed from the Roman god Mercury. The element was known to ancient civilizations, and though its metallic nature was not initially understood, its unique properties led it to be almost invariably seen as special or even imbued with magical powers. Its earliest uses were ceremonial, decorative, or medical; it was used in medical ointments and elixirs, cosmetics, and reflecting pools, and frequently was buried in large quantities alongside dead rulers. Medical uses of mercury are so embedded in some traditional healing practices that some practitioners still recommend the consumption of the mercury ore cinnabar for specific ailments or as a supplement for general health.
It has long been recognized that acute inhalations of mercury can lead to significant symptoms, but it is now understood that the slow elimination of most forms of mercury from the body ensures that even low levels can cause severe damage if chronic exposure allows for significant accumulation. A famous example of such gradual poisonings resulted from the use of mercuric nitrate in processing the animal skins used in 18th and 19th century hatmaking, which led to the coining of the phrase “mad as a hatter.” Increasing recognition of the dangers of chronic mercury exposure and of widespread environmental contamination due to mercury-containing products has driven significant reduction in many classical uses of the element.
Perhaps the most longstanding use of mercury not based primarily on its alluring physical properties was in amalgamation. Mercury will form amalgams with most common metals with the notable exception of iron; as early as 500 BCE this was exploited for extraction or refining of silver and gold. This practice continued in precious metal mining for centuries, though it’s use dwindled with increasing recognition of mercury’s toxicity until ceasing altogether in modern times. Amalgams were also widely used in dental fillings, and are still sometimes used this way today, though both toxicity and cosmetic concerns have led to their increasing replacement by alternative materials.
The pattern of widespread exploitation of unique properties followed by drastic scalebacks or total cessation of use in a given application due to greater recognition of safety risks has repeated throughout mercury’s history. Liquid mercury is opaque, dense, and displays almost-linear thermal expansion, making it ideal for use in instruments for measuring temperature or pressure. It is still used this way in some industrial and technical applications, but has been largely removed from medical equipment and most consumer versions of such products. Additionally, as a liquid that conducts electricity, it was used in mercury switches, which were often used in home light switches and thermostats, but these uses were discontinued. Mercury was also a common component of some types of batteries, but concerns about contaminations of landfills have all but eliminated this use. Mercury sulfide, which occurs naturally as the mineral cinnabar, has been used to produce brilliant warm-colored pigments, most famously “China red”, for centuries and is still used by some artists, but has been replaced by less-toxic pigments for most uses.
Even mercury’s toxicity has been exploited for practical applications. Mercury has been used in insecticides, herbicides, wood preservatives, and anti-fouling paints, but widespread use of all of these products have been discontinued. The organomercury preservative thiomersal was once used widely in vaccines, and though unlike most mercury compounds it produced a metabolite--ethylmercury--that was known to be eliminated from the body relatively quickly and therefore be nontoxic at the extremely low concentrations used in vaccines, public concern about the potential for toxicity has led to its elimination from most formulations. Mercury has also been used as an antiseptic and a diuretic, but these uses are now exceedingly rare and continue to decline.
Reductions in mercury usage in industrial applications have proceeded somewhat more slowly than the elimination of mercury from consumer products. Traditional chloralkali plants use mercury as one electrode in the electrolysis of sodium chloride to produce sodium hydroxide and chlorine gas. New chloralkali plants are required to be designed for use of alternative technology that does not require mercury, but existing plants still consume the majority of mercury produced. Mercury also continues to be used in a number of niche laboratory applications, including liquid mirror telescopes, and in the production of a few compound semiconductor materials used for infrared detection.
A notable exception to the elimination of mercury from consumer products is seen in the proliferation of fluorescent light bulbs which contain small amounts of mercury vapor. The energy efficiency of fluorescent bulbs compared to traditional incandescent lighting is generally considered to be an advantage large enough to outweigh the risks associated with the small amount of mercury the bulbs contain, however such bulbs do require careful disposal, and other energy efficient lighting technologies such as LEDs are beginning to be a competitive alternative for at least some lighting applications.
Mercury occurs naturally in elemental form on occasion, but is mostly found as the sulfide mineral cinnabar. It is extracted from this mineral by roasting to produce mercury vapor and sulfur dioxide. Mercury is also sometimes recovered as a byproduct of silver and gold mining, and recycling of old mercury-containing devices is a significant source of the metal.
- Copper(I) Tetraiodomercurate
- Mercury Phosphate
- Mercuric Potassium Iodide
- Mercury(II) Acetate
- Mercury(II) Amidochloride
- Mercury(II) Benzoate Hydrate
- Mercury(I) Bromate
- Mercury(II) Bromate
- Mercury(I) Bromide
- Mercury(II) Bromide
- Mercury Bromide, Ultra Dry
- Mercury(I) Chloride
- Mercury(II) Chloride
- Mercury(I) Chromate
- Mercury(II) Chromate
- Mercury(II) Cyanide
- Mercury Fluoride
- Mercury(I) Fluoride
- Mercury(II) Fluoride
- Mercury(I) Iodate
- Mercury(II) Iodate
- Mercury(I) Iodide
- Mercury(I) Iodide, Ultra Dry
- Mercury(I) Iodide Yellow
- Mercury(II) Iodide
- Mercury(II) Iodide Red
- Mercury(I) Nitrate Dihydrate
- Mercury(II) Nitrate Monohydrate
- Mercury(II) Nitrate Solution
- Mercury(II) Oxide
- Mercury(I) Perchlorate Tetrahydrate
- Mercury(II) Perchlorate Hydrate
- Mercury(II) Silver Iodide
- Mercury(I) Sulfate
- Mercury(II) Sulfate
- Mercury(II) Sulfide
- Mercury(II) Sulfide Red
- Mercury(II) Tetrathiocyanatocobaltate(II)
- Mercury(II) Thiocyanate
- Mercury(I) Tungstate
- Mercury(II) Tungstate
Mercury is used in the manufacture of industrial chemicals and in electronic applications. For example, mercury is used as gaseous mercury in fluorescent lamps. Some thermometers, particularly those which are used to measure high temperatures, still use mercury. Many of the applications that mercury has been used for in the past are slowly being phased out due to health and safety regulations. Mercury is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Mercury is available in elemental or metallic form as mercury liquid. Mercury oxides are available for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Mercury is also available in soluble forms including chlorides and nitrates. These compounds can be manufactured as solutions at specified stoichiometries.
Mercury is a Block D, Group 12, Period 6 element. The number of electrons in each of Mercury's shells is 2, 8, 18,32, 18, 2 and its electronic configuration is [Xe] 4f14 5d10 6s2. The mercury atom has a radius of 216.pm and its Van der Waals radius is 155.pm. In its elemental form, CAS 7439-97-6, mercury has a silvery appearance. Mercury is found both as a native metal and in cinnabar, corderoite, and livingstonite ores. Mercury was named after the planet "Mercury" and has been known since ancient times.
|Element Category:||transition metal|
|Group, Period, Block:||12, 6, d|
|Color:||silvery white/ silvery-white|
|Other Names:||Mercure, Quecksilber, Mercurio|
|Melting Point:||38.83 °C, 37.89 °F, 234.32 K|
|Boiling Point:||356.73 °C, 674.11 °F, 629.88 K|
|Liquid Density @ Melting Point:||N/A|
|Density @ 20°C:||13.546 g/cm3|
|Density of Solid:||14190 kg·m3|
|Specific Heat:||0.14 (kJ/kg K)|
|Superconductivity Temperature:||3.95 [or -269.2 °C (-452.6 °F)] K|
|Triple Point:||234.3156 K, 1.65×10 7 kPa|
|Critical Point:||1750 K, 172.00 MPa|
|Heat of Fusion (kJ·mol-1):||2.331|
|Heat of Vaporization (kJ·mol-1):||59.11|
|Heat of Atomization (kJ·mol-1):||64.463|
|Thermal Conductivity:||8.30 W·m-1·K-1|
|Thermal Expansion:||(25 °C) 60.4 µm·m-1·K-1|
|Electrical Resistivity:||(25 °C) 961nΩ·m|
|Molar Heat Capacity:||27.983 J·mol-1·K-1|
|Speed of Sound:||(liquid, 20 °C) 1451.4 m·s-1|
|Allred Rochow Electronegativity:||1.44|
|Mulliken-Jaffe Electronegativity:||1.81 (sp orbital)|
|Electron Configuration:||[Xe] 4f14 5d10 6s2|
|Atomic Radius:||151 pm|
|Covalent Radius:||132±5 pm|
|Covalent Radius (Å):||1.32|
|Van der Waals Radius:||155 pm|
|Oxidation States:||4, 2 (mercuric), 1 (mercurous) (mildly basic oxide)|
|Electron Affinity (kJ·mol-1)||Not stable|
|1st Ionization Energy:||1007.07 kJ·mol-1|
|2nd Ionization Energy:||1809.69 kJ·mol-1|
|3rd Ionization Energy:||3299.82 kJ·mol-1|
|Earth - Total:||7.9 ppb|
|Mercury - Total:||0.09 ppb|
|Venus - Total:||8.3 ppb|
|Earth - Seawater (Oceans), ppb by weight:||0.05|
|Earth - Seawater (Oceans), ppb by atoms:||0.0015|
|Earth - Crust (Crustal Rocks), ppb by weight:||67|
|Earth - Crust (Crustal Rocks), ppb by atoms:||7|
|Sun - Total, ppb by weight:||20|
|Sun - Total, ppb by atoms:||0.12|
|Stream, ppb by weight:||0.07|
|Stream, ppb by atoms:||0.0004|
|Meterorite (Carbonaceous), ppb by weight:||250|
|Meterorite (Carbonaceous), ppb by atoms:||20|
|Typical Human Body, ppb by weight:||N/A|
|Typical Human Body, ppb by atom:||N/A|
|Universe, ppb by weight:||1|
|Universe, ppb by atom:||0.006|
|Discovery Date:||Prior to 2000 BC|
Health, Safety & Transportation Information for Mercury
Mercury is very toxic. Safety data for Mercury and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Mercury.
|Material Safety Data Sheet||MSDS|
|Transport Information||UN 2809 8/PG 3|
|Globally Harmonized System of
Classification and Labelling (GHS)
Mercury has seven stable isotopes:
|Nuclide||Isotopic Mass||Half-Life||Mode of Decay||Nuclear Spin||Magnetic Moment||Binding Energy (MeV)||Natural Abundance
(% by atom)
|171Hg||171.00376(32)#||80(30) µs [59(+36-16) µs]||Unknown||3/2-#||N/A||1291.69||-|
|172Hg||171.99883(22)||420(240) µs [0.25(+35-9) ms]||Unknown||0||N/A||1309.09||-|
|173Hg||172.99724(22)#||1.1(4) ms [0.6(+5-2) ms]||Unknown||3/2-#||N/A||1317.17||-|
|174Hg||173.992864(21)||2.0(4) ms [2.1(+18-7) ms]||Unknown||0+||N/A||1325.25||-|
|175Hg||174.99142(11)||10.8(4) ms||α to 171Pt||5/2-#||N/A||1333.33||-|
|176Hg||175.987355(15)||20.4(15) ms||α to 172Pt; β+ to 176Au||0+||N/A||1350.72||-|
|177Hg||176.98628(8)||127.3(18) ms||α to 173Pt; β+ to 177Au||5/2-#||N/A||1358.8||-|
|178Hg||177.982483(14)||0.269(3) s||α to 174Pt; β+ to 178Au||0+||N/A||1366.88||-|
|179Hg||178.981834(29)||1.09(4) s||α to 175Pt; β+ to 179Au; β+ + p to 178Pt||5/2-#||N/A||1374.96||-|
|180Hg||179.978266(15)||2.58(1) s||β+ to 180Au; α to 176Pt; SF||0+||N/A||1392.35||-|
|181Hg||180.977819(17)||3.6(1) s||β+ to 181Au; α to 177Pt; β+ + p to 180Pt; β+ + α to 177Ir||1/2(-)||N/A||1400.43||-|
|182Hg||181.97469(1)||10.83(6) s||β+ to 182Au; α to 178Pt; β+ + p to 181Pt||0+||N/A||1408.51||-|
|183Hg||182.974450(9)||9.4(7) s||β+ to 183Au; α to 179Pt; β+ + p to 182Pt||1/2-||N/A||1416.59||-|
|184Hg||183.971713(11)||30.6(3) s||β+ to 184Au; α to 180Pt||0+||N/A||1424.67||-|
|185Hg||184.971899(17)||49.1(10) s||β+ to 185Au; α to 181Pt||1/2-||N/A||1432.74||-|
|186Hg||185.969362(12)||1.38(6) min||β+ to 186Au; α to 182Pt||0+||N/A||1450.14||-|
|187Hg||186.969814(15)||1.9(3) min||β+ to 187Au; α to 183Pt||3/2-||N/A||1458.22||-|
|188Hg||187.967577(12)||3.25(15) min||β+ to 188Au; α to 184Pt||0+||N/A||1466.3||-|
|189Hg||188.96819(4)||7.6(1) min||β+ to 189Au; α to 185Pt||3/2-||N/A||1474.38||-|
|190Hg||189.966322(17)||20.0(5) min||β+ to 190Au; α to 186Pt||0+||N/A||1482.45||-|
|191Hg||190.967157(24)||49(10) min||β+ to 191Au||3/2(-)||N/A||1490.53||-|
|192Hg||191.965634(17)||4.85(20) h||EC to 192Au; α to 188Pt||0+||N/A||1498.61||-|
|193Hg||192.966665(17)||3.80(15) h||β+ to 193Au||3/2-||N/A||1506.69||-|
|194Hg||193.965439(13)||444(77) y||EC to 194Au||0+||N/A||1514.77||-|
|195Hg||194.966720(25)||10.53(3) h||EC to 195Au||1/2-||0.541475||1522.85||-|
|197Hg||196.967213(3)||64.14(5) h||EC to 197Au||1/2-||0.527374||1539.01||-|
|203Hg||202.9728725(18)||46.595(6) d||β- to 203Tl||5/2-||0.8489||1578.16||-|
|205Hg||204.976073(4)||5.14(9) min||β- to 205Tl||1/2-||N/A||1594.32||-|
|206Hg||205.977514(22)||8.15(10) min||β- to 206Tl||0+||N/A||1602.4||-|
|207Hg||206.98259(16)||2.9(2) min||β- to 207Tl||(9/2+)||N/A||1601.16||-|
|208Hg||207.98594(32)#||42(5) min [41(+5-4) min]||β- to 208Tl||0+||N/A||1609.24||-|
|210Hg||209.99451(32)#||10# min [>300 ns]||Unknown||0+||N/A||1616.08||-|
Recent Research & Development for Mercury
- Mercury poisoning: a case of a complex neuropsychiatric illness. Huang X, Law S, Li D, Yu X, Li B. Am J Psychiatry. 2014 Dec 1
- Observational and modeling constraints on global anthropogenic enrichment of mercury. Amos HM, Sonke JE, Obrist D, Robins N, Hagan N, Horowitz HM, Mason RP, Witt M, Hedgecock I, Corbitt ES, Sunderland EM. Environ Sci Technol. 2015 Mar 9.
- [Antirestriction activity of the mercury resistance nonconjugative transposon Tn5053 is controlled by the protease ClpXP]. [No authors listed] Genetika. 2014 Sep
- Relationships between bacterial energetic metabolism, mercury methylation potential, and hgcA/hgcB gene expression in Desulfovibrio dechloroacetivorans BerOc1. Goñi-Urriza M, Corsellis Y, Lanceleur L, Tessier E, Gury J, Monperrus M, Guyoneaud R. Environ Sci Pollut Res Int. 2015 Mar 14.
- Evaluation of blood and urinary mercury in pemphigus vulgaris and pemphigus foliaceus patients and its comparison with control group. Nikpour S, Yazdanpanah MJ, Afshari R, Maleki M, Ghayour-Mobarhan M, Shakeri MT, Maghami Z, Sadrneshin M, Seidi Z. Indian J Dermatol Venereol Leprol. 2015 Mar-Apr
- Using L-Arginine-Functionalized Gold Nanorods for Visible Detection of Mercury(II) Ions. Guan J, Wang YC, Gunasekaran S. J Food Sci. 2015 Mar 5.
- Mercury speciation in seawater by liquid chromatography-inductively coupled plasma-mass spectrometry following solid phase extraction pre-concentration by using an ionic imprinted polymer based on methyl-mercury-phenobarbital interaction. Rodríguez-Reino MP, Rodríguez-Fernández R, Peña-Vázquez E, Domínguez-González R, Bermejo-Barrera P, Moreda-Piñeiro A. J Chromatogr A. 2015 Mar 3.
- Synergism between exposure to mercury and use of iodine supplements on thyroid hormones in pregnant women. Llop S, Lopez-Espinosa MJ, Murcia M, Alvarez-Pedrerol M, Vioque J, Aguinagalde X, Julvez J, Aurrekoetxea JJ, Espada M, Santa-Marina L, Rebagliato M, Ballester F. Environ Res. 2015 Mar 4
- Spatial and temporal variation of total mercury and methylmercury in lacustrine wetland in Korea. Kim MK, Lee YM, Zoh KD. Environ Sci Pollut Res Int. 2015 Mar 12.
- Effect of laying sequence on egg mercury in captive zebra finches: An interpretation considering individual variation. Ou L, Varian-Ramos CW, Cristol DA. Environ Toxicol Chem. 2015 Mar 11.
- Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania. Grant CJ, Weimer AB, Marks NK, Perow ES, Oster JM, Brubaker KM, Trexler RV, Solomon CM, Lamendella R. J Environ Sci Health A Tox Hazard Subst Environ Eng. 2015 Apr 16
- Novel styrylbenzothiazolium dye-based sensor for mercury, cyanide and hydroxide ions. Gwon SY, Rao BA, Kim HS, Son YA, Kim SH. Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 26
- Placental DNA Methylation Related to Both Infant Toenail Mercury and Adverse Neurobehavioral Outcomes. Maccani JZ, Koestler DC, Lester B, Houseman EA, Armstrong DA, Kelsey KT, Marsit CJ. Environ Health Perspect. 2015 Mar 6.
- Development of magnetic separation and quantum dots labeled immunoassay for the detection of mercury in biological samples. Sun H, Wang M, Wang J, Tian M, Wang H, Sun Z, Huang P. J Trace Elem Med Biol. 2015 Apr
- Umbilical cord blood and placental mercury, selenium and selenoprotein expression in relation to maternal fish consumption. Gilman CL, Soon R, Sauvage L, Ralston NV, Berry MJ. J Trace Elem Med Biol. 2015 Apr
- Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean. Lee S, Kim SJ, Ju SJ, Pak SJ, Son SK, Yang J, Han S. Chemosphere. 2015 Mar 4
- Participation of divalent cation transporter DMT1 in the uptake of inorganic mercury. Vázquez M, Vélez D, Devesa V, Puig S. Toxicology. 2015 Mar 12.
- Zooplankton community changes confound the biodilution theory of methylmercury accumulation in a recovering mercury-contaminated lake. Todorova SG, Driscoll CT, Matthews DA, Effler SW. Environ Sci Technol. 2015 Mar 5.
- Olive-pomace harbors bacteria with the potential for hydrocarbon-biodegradation, nitrogen-fixation and mercury-resistance: Promising material for waste-oil-bioremediation. Dashti N, Ali N, Khanafer M, Al-Awadhi H, Sorkhoh N, Radwan S. J Environ Manage. 2015 Mar 12
- Mercury Poisoning Presenting as Sporadic Creutzfeldt-Jakob Disease: A Case Report. Tang Y, Wang X, Jia J. Ann Intern Med. 2015 Mar 17