![]() ![]() Thermal and physical properties of liquid mercury: Temperature (☌) Solid mercury is malleable and ductile and can be cut with a knife. Upon freezing, the volume of mercury decreases by 3.59% and its density changes from 13.69 g/cm 3 when liquid to 14.184 g/cm 3 when solid. This effect is due to lanthanide contraction and relativistic contraction reducing the radius of the outermost electrons, and thus weakening the metallic bonding in mercury. It has a freezing point of −38.83 ☌ and a boiling point of 356.73 ☌, both the lowest of any stable metal, although preliminary experiments on copernicium and flerovium have indicated that they have even lower boiling points. Compared with other metals, it is a poor conductor of heat, but a fair conductor of electricity. Mercury is a heavy, silvery-white metal that is liquid at room temperature. Properties Physical properties An old pound coin (density ~7.6 g/cm 3) floats on mercury due to the combination of the buoyant force and surface tension. Mercury poisoning is intensified with lead co-exposures. In serious form, it is also known as Minamata disease. 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. 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. In food manufacturing, mercuric chloride is used in the starch extraction process during rice, corn, and wheat refining to inhibit starch degrading enzymes. 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. The mercury cell process ( chlor-alkali) is used to produce chlorine and sodium or potassium hydroxide, but is phased out. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers. 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. ![]() The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide. Mercury occurs in deposits throughout the world mostly as cinnabar ( mercuric sulfide). 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. It is also known as quicksilver and was formerly named hydrargyrum ( / h aɪ ˈ d r ɑːr dʒ ər ə m/ hy- DRAR-jər-əm) from the Greek words hydro (water) and argyros (silver). Be sure to use a pair of curly braces for each subset, and enclose all of them within a pair of outer curly braces.Mercury is a chemical element with the symbol Hg and atomic number 80. (S)\), list the subsets of \(S\) according to their sizes. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |