What does hg stand for on the periodic table

Data for this section been provided by the British Geological Survey. An integrated supply risk index from 1 very low risk to 10 very high risk. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores. The percentage of a commodity which is recycled. A higher recycling rate may reduce risk to supply.

The availability of suitable substitutes for a given commodity. The percentage of an element produced in the top producing country.

The higher the value, the larger risk there is to supply. The percentage of the world reserves located in the country with the largest reserves. A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.

Specific heat capacity is the amount of energy needed to change the temperature of a kilogram of a substance by 1 K. A measure of the stiffness of a substance. It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain. A measure of how difficult it is to deform a material. It is given by the ratio of the shear stress to the shear strain.

A measure of how difficult it is to compress a substance. It is given by the ratio of the pressure on a body to the fractional decrease in volume. A measure of the propensity of a substance to evaporate. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site.

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Jump to main content. Periodic Table. Glossary Allotropes Some elements exist in several different structural forms, called allotropes. Glossary Group A vertical column in the periodic table. Fact box. Glossary Image explanation Murray Robertson is the artist behind the images which make up Visual Elements. Appearance The description of the element in its natural form. Biological role The role of the element in humans, animals and plants.

Natural abundance Where the element is most commonly found in nature, and how it is sourced commercially. Uses and properties. Image explanation. The image is of a traditional alchemical symbol for mercury. This is also an astrological symbol for the planet Mercury.

The dragon or serpent in the background comes from early alchemical drawings and is often associated with the element. Mercury has fascinated people for millennia, as a heavy liquid metal.

However, because of its toxicity, many uses of mercury are being phased out or are under review. It is now mainly used in the chemical industry as catalysts. It is also used in some electrical switches and rectifiers. Previously its major use was in the manufacture of sodium hydroxide and chlorine by electrolysis of brine. These plants will all be phased out by It was also commonly used in batteries, fluorescent lights, felt production, thermometers and barometers.

Again, these uses have been phased out. Mercury easily forms alloys, called amalgams, with other metals such as gold, silver and tin. The ease with which it amalgamates with gold made it useful in recovering gold from its ores. Mercury amalgams were also used in dental fillings.

Mercuric sulfide vermilion is a high-grade, bright-red paint pigment, but is very toxic so is now only used with great care. Biological role. Mercury has no known biological role, but is present in every living thing and widespread in the environment. Every mouthful of food we eat contains a little mercury. Our daily intake is less than 0.

However, in much higher doses it is toxic and one form of mercury — methylmercury — is particularly dangerous. It can accumulate in the flesh of fish and be eaten by people, making them ill. Natural abundance. Mercury rarely occurs uncombined in nature, but can be found as droplets in cinnabar mercury sulfide ores. China and Kyrgyzstan are the main producers of mercury. The metal is obtained by heating cinnabar in a current of air and condensing the vapour.

Help text not available for this section currently. Elements and Periodic Table History. Cinnabar aka vermilion, mercury sulfide, HgS , was used as a bright red pigment by the Palaeolithic painters of 30, years ago to decorate caves in Spain and France.

Cinnabar would yield up its mercury simply on heating in a crucible, and the metal fascinated people because it was a liquid that would dissolve gold. The ancients used in on a large scale to extract alluvial gold from the sediment of rivers. Other common mercury compounds include mercuric chloride HgCl 2 — a highly poisonous salt and that was once used as a wound disinfectant. Another example is mercurous chloride Hg 2 Cl 2 , also known as calomel — an antiseptic used to kill bacteria, according to the Jefferson Lab.

Mercuric sulfide HgS is used to make a red paint pigment called vermilion, and mercuric oxide HgO is used to make mercury batteries. Due to mercury's toxic potential, researchers keep stumbling upon ways in which the element may be harmful to humans and the environment. For example, scientists have argued about the potential toxicity of amalgam used in dental fillings that contains about 50 percent mercury. In a review of literature published in in the journal Gesundheitswesen, researchers found that exposure to mercury in dental fillings could lead to kidney and autoimmunity problems, neurobehavioral changes and even autism.

However, in another review , published in the Journal of the Canadian Dental Association, investigators came to a different conclusion, stating that: "The amount of mercury released from dental amalgam is minimal; a person would have to have amalgam surfaces for there to be enough mercury vapor and ionic mercury given off from amalgam fillings to meet the maximum exposure guidelines.

Upon reviewing scientific evidence, the FDA concluded that "dental amalgam fillings safe for adults and children ages 6 and above," according to the agency's website. There is also a growing body of research on methylmercury — the most toxic form of mercury — and its harmful effects on the environment and human health. People get exposed to methylmercury mainly through eating contaminated fish and seafood that pick up the toxic compound from the ocean.

Elemental mercury, the same form of mercury that can be found in thermometers, gets converted into methylmercury by ocean bacteria. Methylmercury is particularly dangerous to developing embryos, which are five to 10 times more sensitive to its damaging effects on the nervous system than adults, according to the U. Geological Survey.

Mercuric oxide is used in skin ointments. Mercuric sulphate is used as a catalyst in organic chemistry. Vermilion, a red pigment, is mercuric sulphide; another crystalline form of the sulphide also used as a pigment is black. Mercury fulminate, Hg CNO 2 , is used as a detonator. Mercury occurs uncombined in nature to a limited extent.

World production of mercury is around 8. Mineable reserves are around Mercury is a compound that can be found naturally in the environment. It can be found in metal form, as mercury salts or as organic mercury compounds.

Mercury enters the environment as a result of normal breakdown of minerals in rocks and soil through exposure to wind and water. Release of mercury from natural sources has remained fairly the same over the years. Still mercury concentrations in the environment are increasing; this is ascribed to human activity. Most of the mercury released from human activities is released into air, through fossil fuel combustion, mining, smelting and solid waste combustion. Some forms of human activity release mercury directly into soil or water, for instance the application of agricultural fertilizers and industrial wastewater disposal.

All mercury that is released in the environment will eventually end up in soils or surface waters. Mercury is not naturally found in foodstuffs, but it may turn up in food as it can be spread within food chains by smaller organisms that are consumed by humans, for instance through fish. Mercury concentrations in fish usually greatly exceed the concentrations in the water they live in. Cattle breeding products can also contain eminent quantities of mercury.

Mercury is not commonly found in plant products, but it can enter human bodies through vegetables and other crops, when sprays that contain mercury are applied in agriculture. Metallic mercury is used in a variety of household products, such as barometers, thermometers and fluorescent light bulbs.