Elements

Periodic Table Elements - Basic description

Al - Aluminum

A common metal comprising nearly ten percent of the crust of the earth, aluminum has been known since its preparation by Hans Oerstead 1825. Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. It is somewhat decorative. It is easily formed, machined, and cast. Pure aluminium is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminium is an abundant element in the earth's crust, but it is not found free in nature. The Bayer process is used to refine aluminium from bauxite, an aluminium ore.

Ar - Argon

Argon is an inert gas used for its blue and green lumination of emission. Argon was found in 1894 by William Ramsey and Rayleigh in an experiment in which they removed all of the oxygen and nitrogen from the air. Argon is colourless and odourless. Argon is very inert and is not known to form true chemical compounds. It makes a good atmosphere for working with air-sensitive materials since it is heavier than air and less reactive than N2. Argon is present to a small extent in the atmosphere and is obtained as a byproduct from the liquefaction and separation of air. This would not normally be carried out in the laboratory since argon is available commercially in cylinders at high pressure.

As - Arsenic

This metaloid has been known for its toxic properties since the 1200's. Elemental arsenic occurs in two solid modifications: yellow, and grey or metallic, with specific gravities of 1.97, and 5.73, respectively. The element is a steel grey, very brittle, crystalline, semimetallic (metalloid) solid. It tarnishes in air, and when heated rapidly oxidises to arsenous oxide which has a garlic odour. Arsenic and its compounds are poisonous as any reader of "who-done-it" books knows. Upon heating arsenic and some minerals containing arsenic, it sublimes (transfers from the solid to the gaseous state, without passing through the liquid state).

Ag - Silver

The precious metal silver was known to the ancients. Uses of silver and its compounds include ornamentation, electronics and antibacterial agents. Silver is somewhat rare and expensive, although not as expensive as gold. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that man learned to separate silver from lead as early as 3000 B.C. Pure silver has a brilliant white metallic lustre. It is a little harder than gold and is very ductile and malleable. Pure silver has the highest electrical and thermal conductivity of all metals, and possesses the lowest contact resistance. Silver iodide, AgI, is (or was?) used for causing clouds to produce rain. Silver is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulphide, or air containing sulphur. It occurs in ores including argentite, lead, lead-zinc, copper and gold found in Mexico, Peru, and the USA.

Au - Gold

A precious metal. Once used only for money and ornimentation, gold has found many uses in modern technology. The free metal is not very reactive and is often found in electronics and micromechanics. Compounds, notably the chloride, are used in archival photoprocessing and analytical chemistry.It is the most malleable and ductile metal; 1 ounce (28 g) of gold can be beaten out to 300 square feet. It is a soft metal and is usually alloyed to give it more strength. It is a good conductor of heat and electricity, and is unaffected by air and most reagents.

At - Astatine

Discovered by Corson, etal., in 1940. The longest-lived isotope, 210At, has a half-life of only 8.3 hours. There are about 20 isotopes known, all of which are radioactive. Astatine is a halogen and possibly accumulates in the thyroid like iodine. Astatine is radioactive and essentially unavailable in nature. It is not possible to make other than in a nuclear reactor.

Ac - Actinium

Discovered by Debierne, 1899.Actinium is dangerously radioactive. The chemical behaviour of actinium is similar to that of the rare earths, particularly lanthanum. It is found naturally in uranium ores and actinium is 150 times more radioactive than radium.

Am - Americium

Named after America. it was discovered by Glenn Seaborg in 1944 in Berkeley. Americium appears to be more malleable than uranium or neptunium and americium tarnishes slowly in dry air at room temperature. Americium is a radioactive rare earth metal which must be handled with care to avoid contact, since it is a heavy a and g emitter. The a activity of 241Am is about three times that of radium.A tiny amount of americium provides electrons in smoke detectors. Americium is available to qualified users in the UK and in the USA.

Be - Beryllium

Beryllium is an alkaline earth metal, many compounds of which are toxic. Discovery of the element in the mineral beryl, was reported by Nicolas Louis Vauquelin in 1789. Beryllium metal was isolated by Wöhler and Bussy in 1828. Little known fact: the speed of sound in beryllium (12,500 m/s) is greater than in any other element.

B - Boron

Black amorphous boron powder was isolated from borax by Joseph Louis Gay-Lussac (with Thenard) and independently by Davy in 1808. Hard, red crystals of pure boron were not produced for almost one hundred years. Aluminum borohydride and boron trihydride are used as reducing agents in organic chemistry.

Br - Bromine

The liquid halogen bromine was extracted from seawater in 1826 by Antoine Jèrôme Balard. Bromine is the only liquid nonmetallic element. It is a member of the halogen group. It is a heavy, volatile, mobile, dangerous reddish-brown liquid. The red vapour has a strong unpleasant odour and the vapour irritates the eyes and throat. It is a bleaching. When spilled on the skin it produces painful sores. It is a serious health hazard, and maximum safety precautions should be taken when handling it.

Ba - Barium

An alkaline earth element, barium is also a toxic heavy metal. Minerals containing barium were identified by Karl Scheele in 1774 from which the pure metal was electrolysed by Humphrey Davy in 1808. Barium is a metallic element, soft, and when pure is silvery white like lead. The metal oxidises very easily and it reacts with water or alcohol. Barium is one of the alkaline-earth metals. Small amounts of barium compounds are used in paints and glasses.

Bi - Bismuth

A heavy metal, bismuth has been known since Claude Geoffroy distinguished it from lead in 1753. Bismuth is a white, crystalline, brittle metal with a pinkish tinge. Bismuth is the most diamagnetic of all metals, and the thermal conductivity is lower than any metal, except mercury. It has a high electrical resistance, and has the highest Hall effect of any metal (that is, the greatest increase in electrical resistance when placed in a magnetic field).

Bh - Bohrium

An artificial element, discovered by Peter Armbruster and Gottfried Münzenberg in 1981. Named after Neils Bohr. Bohrium is a synthetic element that is not present in the environment at all. Isolation of an observable quantity of bohrium has never been achieved, and may well never be. This is because bohrium decays very rapidly through the emi

Bk - Berkelium

It was produced by Thompson, Ghiorso and Seaborg in Berkeley, of all places, in 1949. Berkelium is a radioactive rare earth metal, named after the University of California at Berkeley (USA). Apparently, berkelium tends to accumulate in the skeletal system. It is of no commercial importance and only a few of its compounds are known.

C - Carbon

Although the name carbon comes from Roman times, the non-metallic element has been known, as charcoal, coal, diamonds and soot, since the dawn of mankind. More compounds known to us contain carbon than all the other elements combined, so naturally carbon compounds abound in our laboratory. Except for carbonates which were discovered in minerals, compounds that contain carbon are called organic compounds. Carbon dioxide and several carbonates are used infundamental chemistry as are carbon containing alcohols and oils. A variety of organic compounds are encountered in general chemistry. More complex organic compounds are studied in Chemistry and Society and, naturaly, organic chemistry.

Cl - Chlorine

A green, highly reactive gas, chlorine is the most abundant halogen, comprising nearly two percent of the seas. Karl Scheele discovered chlorine in 1774, but believed it to be an oxide of a ficticous element, murium (which is why hydrochloric acid is also known as muriatic acid.) Murium was never found, but Humphrey Davy recognized it's elemental quality in 1810.

Ca - Calcium

Although compounds of the alkaline earth metal have been used since the days of the pharaohs, pure calcium metal was not obtained until Humphrey Davy electrolyzed it from a salt in 1808. Calcium is a metallic element, fifth in abundance in the earth's crust, of which it forms more than 3%. It is an essential constituent of leaves, bones, teeth, and shells. The metal is a silvery colour and is rather hard. Chemically it is one of the alkaline earth elements; it readily forms a white coating of nitride in air, reacts with water, burns with a yellow-red flame, forming largely the nitride. Calcium does not occur free in nature. Calcium is found mostly as limestone, gypsum and fluorite. Stalagmites and stalactites contain calcium carbonate.

Cr - Chromium.

This transition metal was discovered by Vanquelin in 1790. Chromium is steel-gray, lustrous, hard, metallic, and takes a high polish. Its compounds are toxic. It is found as chromite ore. Siberian red lead (crocoite, PrCrO4) is a chromium ore prized as a red pigment for oil paints. Modern uses include high strength alloys and metal finishing applications.

Co - Cobalt

A transition metal, discovered by Brandt in 1735. Cobalt is a brittle, hard, transition metal with magnetic properties similar to those of iron. Cobalt is present in meteorites. Ore deposits are found in Zaire, Morocco and Canada. Cobalt-60 (60Co) is an artificially produced isotope used as a source of g rays (high energy radiation). Cobalt salts colour glass a beautiful deep blue colour.

Cu - Copper

As the transition metal copper can be found pure in nature, it was known to the ancients. Originally popular for its high malleability, the extremely high electrical conductivity of copper (second only to silver) makes it the conductor of choice for most wires.

Cd - Cadmium

This toxic metal was discovered by Fredrich Strohmeyer in 1817, who was heating zinc carbonate (formerly known as kadmia) to remove impurities. Cadmium is a soft, bluish-white metal and is easily cut with a knife. It is similar in many respects to zinc. Interestingly, aa characteristic cadmium "scream" is heard on bending a cadmium bar. Cadmium and its compounds are highly toxic. Silver solder, which contains cadmium, should be handled with care.

Cs - Cesium

Cesium was discovered by G. R. Kirchhoff and Robert Bunsen spectroscopicaly in 1860. The metal is characterised by a spectrum containing two bright lines in the blue (accounting for its name). It is silvery gold, soft, and ductile. It is the most electropositive and most alkaline element. Caesium, gallium, and mercury are the only three metals that are liquid at or around room temperature. Caesium reacts explosively with cold water, and reacts with ice at temperatures above -116°C. Caesium hydroxide is a strong base and attacks glass.Caesium is known as cesium in the USA.

Ce - Cerium

This rare earth element was named after the planetoid Ceres which was found the year before cerium was discovered, 1803, by Berzelius and Hisinger. Pure cerium was produced in 1875 by Hillebrand and Norton. Metallic cerium is prepared by reduction techniques, such as by reducing cerous fluoride with calcium, or by electrolysis of molten cerous chloride or other cerous halides. Cerium is an iron-grey lustrous metal. It is malleable, and oxidises very readily at room temperature, especially in moist air. Except for europium, cerium is the most reactive of the rare-earth metals. It slowly decomposes in cold water, and rapidly in hot water. Alkali solutions and dilute and concentrated acids attack the metal rapidly. The pure metal may ignite when scratched with a knife. It is the most abundant of the rare earth metals and is found in minerals including allanite, monazite, cerite, and bastnaesite. There are large deposits found in India, Brazil and the USA.

Cf - Californium

.Discovered by Thompson, Ghiorso, Seaborg and Street in 1950, Berkeley. Californium is a radioactive rare earth metal named after the state of California and the University of California (USA). Californium-252 is a strong neutron emitter and one microgram emits 170 million neutrons per minute, making it a biological hazard. It has a few specialised uses but only a few of its compounds are known.

Cm - Curium

Discovered by Seaborg, James and Ghiorso in 1944. Most compounds of Cm(III) are faintly yellow. If curium enters the body it accumulates in the bones, and is therefore very toxic as its radiation destroys the red-cell forming mechanism. Curium is a radioactive rare earth metal. The most stable isotope is 247Cm which has a half-life of 16 million years. Curium is probably present in uranium ores. It has a few specialised uses but only a few of its compounds are known.

Db - Dubnium

An artifical element. Dubnium was discovered by Ghiorso and co-workers. Named for Dubna, a Russian town north of Moscow that is home to the Joint Institutes of Nuclear Research. Dubnium is a synthetic element that is not present in the environment at all. It has no uses.

Dy - Dysprosium

The rare earth metal dysprosium was discovered by de Boisbaudrain in 1886. Dysprosium is a component of glass blowers spectacles. The element has a metallic, bright silver lustre. It is relatively stable in air at room temperature, but dissolves readily, with the evolution of hydrogen, in mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. It is a rare earth metal found in minerals such as xenotime, monazite and bastanite.

Eu - Europium

Discovered by Demarçay in 1901. Europium ignites in air at about 150 to 180°C. Europium is about as hard as lead and is quite ductile. It is the most reactive of the rare earth metals, quickly oxidising in air. It resembles calcium in its reaction with water. It is used in television screens to produce a red colour.

Er - Erbium

The rare earth metal, erbium was discovered by Mosander in 1842. Pure erbium metal is soft and malleable and has a bright, silvery, metallic lustre. As with other rare-earth metals, its properties depend to a certain extent on impurities present. The metal is fairly stable in air and does not oxidise as rapidly as some of the other rare-earth metals.

Es - Einsteinium

Einsteinium is radioactive rare earth metal named after Albert Einstein. It was discovered at Los Alamos University in 1952 by bombarding uranium with neutrons. It is of no commercial importance and only a few of its compounds are known.

F - Fluorine

Fluorine was discovered by Karl Scheele in 1771 but not isolated until 1886 when Henri Moissan electrolysed potassium fluoride with some very sophisitcated and expensive equipment. Fluorine is a Group 17 element. Fluorine is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame. Until World War 2, there was no commercial production of elemental fluorine. Atom bomb projects and nuclear energy applications made it necessary to produce large quantities of fluorine since isotopes of uranium can be separated through the gas diffusion of UF6. Reasonably safe handling techniques for fluorine are now available and one can transport liquid fluorine by the ton. Compounds of fluorine with noble gases such as xenon, radon, and krypton are known. Elemental fluorine and the fluoride ion (in quantity) are highly toxic.

Fe - Iron

The Iron Age was underway by 1000 BC; since then, the history of our technology based civilization has been the history of iron. Iron's strength was its first virtue and it's ferromagnetic properties are a gift. Iron is not without drawbacks, however. When in the presence of water, iron readily reacts with oxygen, making rust: a brittle, flimsy, red powder which is mostly useless.

Fr - Francium

Rare, reactive and radioactive, francium is hard to come by - only about a tenth of a mole exists at any time. Possibly observed in 1931 by Fred Allison, who called it virginium, the element was discovered and confirmed in 1939 by Marguerite Perey, in decay products of actinium. . Francium is found in uranium minerals, and can be made artificially by bombarding thorium with protons. It is the most unstable of the first 101 elements. The longest lived isotope, 223Fr, a daughter of 227Ac, has a half-life of 22 minutes. This is the only isotope of francium occurring in nature, but at most there is only 20-30 g of the element present in the earth's crust at any one time. No weighable quantity of the element has been prepared or isolated. There are about 20 known isotopes.

Fm - Fermium

Fermium was discovered by Choppin, Thompson, Ghioros and Harvey in 1952.Fermium's chemical properties are largely unknown. Fermium is a radioactive rare earth metal. The longest living isotope is is 257Fm with a half-life of 80 days. It is of no commercial importance.

Ga - Gallium

Gallium was discovered by Lecoq de Boisbaudrain in 1875 in Paris. It is the only metal, except for mercury, caesium, and rubidium, which can be liquid near room temperatures; this makes possible its use in high-temperature thermometers. It has one of the longest liquid ranges of any metal and has a low vapour pressure even at high temperatures.

Ge - Germanium

Germanium, discovered by Winkler in 1886. The element is a gray-white metalloid, and in its pure state is crystalline and brittle, retaining its lustre in air at room temperature. It is a very important semiconductor material. Zone-refining techniques have led to production of crystalline germanium for semiconductor use with an impurity of only one part in 10-10.

Gd - Gadolinium

This rare earth metal was discovered by J. C. G. de Marignac in 1880, who named the metal for Finnish geologist, J. Gadolin. Except for fourth period transition metals, gadolinium is the only metal to exhibit ferromagnetic properties (strongly attracted by a magnet). Gadolinium is silvery white, has a metallic lustre, and is is malleable and ductile. The metal is relatively stable in dry air, but in moist air it tarnishes with the formation of a loosely adhering oxide film which "spalls" off and exposes more surface to oxidation. The metal reacts slowly with water and is soluble in dilute acid. Gadolinium has the highest thermal neutron capture cross-section of any known element.

H - Hydrogen

Henry Cavendish discovered that hydrogen was an element in 1766. This flammable gas the is the most abundant element in the universe making up about about 90% of the universe by weight. Hydrogen as water (H2O) is absolutely essential to life and it is present in all organic compounds. Hydrogen gas was used in lighter-than-air balloons for transport but proved far too dangerous because of the fire risk. The lifting agent for the ill fated Hindenberg airship was hydrogen rather than the safer helium.

He - Helium

Helium was discovered in 1868 by J. Norman Lockyear in the spectrum of a solar eclipse. Helium is one of the so-called noble gases and is a light, inert, colourless, and odourless gas and the second most abundant element in the universeis after hydrogen. Helium is used in lighter than air balloons and while heavier than hydrogen, is far safer since helium does not burn.

Hf - Hafnium

The transition element Hafnium was discovered by Coster and Hevesey in 1923 in Denmark. Most zirconium minerals contain 1 to 3% hafnium. Hafnium is a ductile metal with a brilliant silver lustre. Its properties are influenced considerably by the impurities of zirconium present. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Hafnium is a Group 4 transition element. Because hafnium has a good absorption cross section for thermal neutrons (almost 600 times that of zirconium), has excellent mechanical properties, and is extremely corrosion resistant, it is used for nuclear reactor control rods. Hafnium carbide is the most refractory binary composition known, and the nitride is the most refractory metal nitride (m.p. 3310°C).

Hg - Mercury

Famous for its toxic properties and it's physical state, mercury is a liquid heavy metal. Mercury is the only common metal liquid at ordinary temperatures. Mercury is sometimes called quicksilver. It rarely occurs free in nature and is found mainly in cinnabar ore (HgS) in Spain and Italy. It is a heavy, silvery-white liquid metal. It is a rather poor conductor of heat as compared with other metals but is a fair conductor of electricity. It alloys easily with many metals, such as gold, silver, and tin. These alloys are called amalgams. Its ease in amalgamating with gold is made use of in the recovery of gold from its ores.

Hs - Hassium

An artificial element, discovered by Peter Armbruster and Gottfried Münzenberg in 1983. Hassium, is a synthetic element that is not present in the environment at all.

Ho - Holmium

Holmium is named for Stockholm. Discovered by Per Cleve in 1878 near there. Holmium is relatively soft and malleable, and is stable in dry air at room temperature. It oxidises rapidly in moist air and at elevated temperatures. The metal has unusual magnetic properties. The metal is a rare earth metal found in monazite, gadolinite and other minerals.

I - Iodine

The solid halogen was discovered in 1811 by Bernard Courtois in seaweed. Iodine has been used for its antibacterial qualities. Iodine is a bluish-black, lustrous solid. It volatilises at ambient temperatures into a pretty blue-violet gas with an irritating odour. It forms compounds with most elements, but is less reactive than the other halogens, which displace it from iodides. Iodine exhibits some metallic-like properties. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulphide to form beautiful purple solutions. It is only slightly soluble in water. Iodine compounds are important in organic chemistry and very useful in medicine and photography. Lack of iodine is the cause of goitre (Derbyshire neck). The deep blue colour with starch solution is characteristic of the free element. It is assimilated by seaweeds from which it may be recovered, and is found in Chilean saltpetre, caliche, old salt brines, and salt wells.

In - Indium

Discovered by Seaborg, James and Ghiorso in 1944. Indium is a very soft, silvery-white metal with a brilliant lustre. The pure metal gives a high-pitched "scream" when bent. It wets glass, as does gallium. It is useful for making low-melting alloys. An alloy of 24% indium and 76% gallium is liquid at room temperature. Canada produces the majority of of the world's supply of indium.

Ir - Iridium

This precious transition metal was discovered by Tennant in 1803 in England. Iridium is white, similar to platinum, but with a slight yellowish cast. It is very hard and brittle, making it very hard to machine, form, or work. It is the most corrosion resistant metal known, and was used in making the standard metre bar of Paris, which is a 90% platinum-10% iridium alloy. This metre bar has since been replaced as a fundamental unit of length.

K - Potassium

In 1807, Humphrey Davy electrolyzed "fused potash" (KOH) to form pure potassium at the cathode. Potassium, also known as kalium, is a soft alkali metal and one of the most active metals known. The metal is the seventh most abundant and makes up about 1.5 % by weight of the earth's crust. Potassium is an essential constituent for plant growth and it is found in most soils. It is also a vital element in the human diet. Potassium is never found free in nature, but is obtained by electrolysis of the chloride or hydroxide, much in the same manner as prepared by Davy. It is one of the most reactive and electropositive of metals and, apart from lithium, it is the least dense known metal. It is soft and easily cut with a knife. It is silvery in appearance immediately after a fresh surface is exposed. It oxidises very rapidly in air and must be stored under argon or under a suitable mineral oil. As do all the other metals of the alkali group, it decomposes in water with the evolution of hydrogen. It usually catches fire during the reaction with water. Potassium and its salts impart a lilac colour to flames.

Kr - Krypton

The rare gas krypton (and neon, xenon and radon.) was extracted by William Ramsey and M. W. Travers from liquid air in 1898. The name krypton means hidden. Known compounds include a hydrate, deuteride and the difluoride. Krypton is present in the air at about 1 ppm. The atmosphere of Mars contains a little (about 0.3 ppm) of krypton. It is characterised by its brilliant green and orange spectral lines. The spectral lines of krypton are easily produced and some are very sharp. In 1960 it was internationally agreed that the fundamental unit of length, the metre, should be defined as 1 m = 1,650,763.73 wavelengths (in vacuo) of the orange-red line of Kr-33. Under normal conditions krypton is colourless, odourless, fairly expensive gas. Solid krypton is a white crystalline substance with a face-centered cubic structure which is common to all the "rare gases". Krypton difluoride, KrF2, has been prepared in gram quantities and can be made by several methods.

Li - Lithium

The light metal, lithium, was discovered in mineral compounds, by August Arfvedson in 1817 and electrolyticaly purified by Sir Humphrey Davy (also, independantly by Brandé) in 1818. Lithium is a Group 1 (IA) element containing just a single valence electron (1s22s1). Group 1 elements are called "alkali metals". Lithium is a solid only about half as dense as water. A freshly cut chunk of lithium is silvery, but tarnishes in a minute or so in air to give a grey surface. Lithium is mixed (alloyed) with aluminium and magnesium for light-weight alloys, and is also used in batteries, some greases, some glasses, and in medicine.

La - Lanthanum

The element was discovered by Mosander in 1839 in Sweden. Lanthanum is silvery white, malleable, ductile, and soft enough to be cut with a knife. It is one of the most reactive of the rare-earth metals. It oxidises rapidly when exposed to air. Cold water attacks lanthanum slowly, and hot water attacks it much more rapidly. The metal reacts directly with elemental carbon, nitrogen, boron, selenium, silicon, phosphorus, sulphur, and with halogens. It is a component of, misch metal (used for making lighter flints).

Lu - Lutetium

A rare earth metal discovered in 1907 by Urbain in France and James at the University of New HAmpshire. Pure metal lutetium has been isolated only in recent years and is one of the more difficult to prepare. It can be prepared by the reduction of anhydrous LuCl3 or LuF3 by an alkali or alkaline earth metal. The metal is silvery white and relatively stable in air. It is a rare earth metal and perhaps the most expensive of all rare elements. It is found in small amounts as with all rare earth metals, and is very difficult to separate from other rare elements.

Lr - Lawrencium

Lawrencium was discovered in 1961 by Ghiorso, Sikkeland, Larsh and Latimer at Berkeley. The longest lived isotope, Lr256 forms +3 ions. Lawrencium is a synthetic "rare earth metal" which does not occur in the environment.

Mg - Magnesium

A flammable and light weight alkaline earth metal. Joseph Black discovered the element in 1755 in Scotland, and Davy produced the pure metal with his electrolytic apperatus in 1808. Industrially, magnesium is used extensively in lightweight alloys. Ions of magnesium are essential for most organisms. Magnesium is the eighth most abundant element in the earth's crust although not found in it's elemental form. It is a Group 2 element (Group IIA in older labelling schemes). Group 2 elements are called alkaline earth metals. Magnesium tarnishes slightly in air, and finely divided magnesium readily ignites upon heating in air and burns with a dazzling white flame. Normally magnesium is coated with a layer of oxide, MgO, that protects magnesium from air and water.

Mn - Manganese

A transition metal. The metal discovered in 1770 by Ignatius Kaim, investigated by Bergman and Scheele and finally isolated by swedish mineralist Johann Gottlieb Gahn. The metal is gray-white, resembling iron, but is harder and very brittle. The metal is reactive chemically, and decomposes cold water slowly. Manganese is widely distributed throughout the animal kingdom. It is an important trace element and may be essential for utilisation of vitamin B. Manganese is present in quantity on the floor of oceans. It is an important component of steel.

Mo - Molybdenum

Molybdenum is a silvery-white, hard, transition metal, discovered by Scheele in 1778 and extracted in metallic form in 1783 by P. H. Hjelm in Sweden. It was often confused with graphite and lead ore. Molybdenum is used in alloys, electrodes and catalysts. The World War 2 German artillery piece called "Big Bertha" contains molybdenum as an essential component of its steel.

Mt - Meitnerium

An artifical element named after Lise Meiter. Discovered by Peter Armbruster and Gottfried Münzenberg in 1984. Element 109, meitnerium, is a synthetic element that is not present in the environment at all.

Md - Mendelevium

Synthesis in 1955 by alpha bombardment of einsteinium by Albert Ghiorso with Harvey, Choppin, Thompson and Glenn Seaborg at Berkeley. Mendelevium is a radioactive rare earth metal named after Dmitri Mendeleev, father of the Periodic Table.

N - Nitrogen

The gas, nitrogen occupies 78 percent of our atmosphere, Mars in comparison contains less than 3% nitrogen.It was not known until "mephitic air" was discovered by Daniel Rutherford in Scotland (and others, independently) in 1772. The inability of nitrogen to support combustion was the cause of its discovery. Nitrogen is a Group 15 element. The element seemed so inert that Lavoisier named it azote, meaning "without life". However, its compounds are vital components of foods, fertilizers, and explosives. Nitrogen gas is colourless, odourless, and generally inert. As a liquid it is also colourless and odourless. When nitrogen is heated, it combines directly with magnesium, lithium, or calcium. When mixed with oxygen and subjected to electric sparks, it forms nitric oxide (NO) and then the dioxide (NO2). When heated under pressure with hydrogen in the presence of a suitable catalyst , ammonia forms (Haber process). Nitrogen is "fixed" from the atmosphere by bacteria in the roots of certain plants such as clover. Hence the usefulness of clover in crop rotation.

Ne - Neon

This inert gas is well known for its orange light seen in 'neon signs'. Neon (as well as krypton, xenon and radon.) was extracted by William Ramsey and M. W. Travers from liquid air in 1898 in London. It is a very inert element. Neon forms an unstable hydrate. In a vacuum discharge tube, neon glows reddish orange. Of all the rare gases, the discharge of neon is the most intense at ordinary voltages and currents. It is present in the atmosphere as 1 part in 65000. Liquid neon has over 40 times more refrigerating capacity than liquid helium, and more than 3 times that of liquid hydrogen.

Na - Sodium

Sodium (aka natrium) is a ubiquitous, alkali metal. Humphrey Davy electrolysed pure sodium from sodium hydroxide in 1807 in London. Soap is generally a sodium salt of fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times. The most common compound is sodium chloride, (table salt).

Ni - Nickel

Coins made from this transition metal were minted in 235 BC in China. In 1751 A. Cronstedt was able to purify the element. Nickel is found as a constituent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals. Iron meteorites, or siderites, may contain iron alloyed with from 5 to nearly 20% nickel. The USA 5-cent coin (whose nickname is "nickel") contains just 25% nickel. Nickel is a silvery white metal that takes on a high polish. It is hard, malleable, ductile, somewhat ferromagnetic, and a fair conductor of heat and electricity. Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas and exposure should not exceed 0.007 mg M-3.

Nb - Niobium

A transition metal, discovered by Hatchett in 1801 in London. Niobium was formerly known as columbium.The name niobium was adopted officially by IUPAC in 1950, but a few commercial producers still like to refer to it as columbium. Niobium is a shiny, white, soft, and ductile metal, and takes on a bluish tinge when exposed to air at room temperatures for a long time. The metal starts to oxidize in air at high temperatures, and when handled hot must be done so under a protective atmosphere so as to minimize oxide production.

Nd - Neodymium

Baron von Welsbach separated the components of dydimium into neodymium (the new twin) and praseodymium (the green twin) in 1885 in Vienna. Neodymium is present in misch metal to the extent of about 18%. The metal has a bright silvery metallic lustre. Neodymium is one of the more reactive rare-earth metals and quickly tarnishes in air, forming an oxide that spalls off and exposes the metal to further oxidation. It is one of the rare earth metals.

No - Nobelium

This artificial actinide was first reported by Fields in 1957 in Stockholm.Nobelium is a radioactive "rare earth metal" named after Alfred Nobel who discovered dynamite.

Np - Neptunium

Neptunium was produced by E. M. McMillan (who shared the 1951 Nobel Prize for Chemistry with Glenn Seaborg for the discovery of this and other transuranic elements) and P. Abelson in 1940 at Berkeley, and found naturally occuring in trace amounts in uranium minerals by Seaborg and Perlman in 1948. Neptunium is a radioactive rare earth metal and has at least 3 allotropic forms. It is named for the planet Neptune. Np-237 is a by-product from nuclear reactors.

O - Oxygen

Oxygen gas was discovered by Swedish pharmacist, Karl Scheele in 1771. Oxygen is prepared in fundamental chemistry using the same process Scheele, Priestley and Lavoisier (who named the element) employed. Comprising 87 percent of the oceans, one fifth of the atmosphere and six out of ten atoms on the crust, oxygen is the most abundant element on the surface of the earth.

Os - Osmium

A precious metal. Osmium is used in ball pens, as a forensic stain, and in electronic applications. Discovered in 1804 by Englishman Smithson Tennent in the residue left by dissolving platinum in aqua regia. A comprehensive guide to the simple chemistry of the metal can be found in The Chemistry of the Rarer Platinum Metals (John Wiley, New York, 1967).
Powdered osmium is oxidized in air at room temperature to form highly toxic osmium tetroxide. Found naturally with iridium, paladium, rhodium and platinum.

P - Phosphorus

The flammable non-metal was discovered in Germany in 1669 by Hennig Brand who precipitated it from urine. Phosphorus is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm. Phosphorus exists in several allotropic forms including white (or yellow), red, and black (or violet). White phosphorus has two modifications. Ordinary phosphorus is a waxy white solid. When pure, it is colourless and transparent. It is insoluble in water, but soluble in carbon disulphide. It catches fire spontaneously in air, burning to P4O10, often misnamed as phosphorus pentoxide. When exposed to sunlight, or when heated in its own vapour to 250°C, it is converted to the red variety. This form does not ignite spontaneously and it is a little less dangerous than white phosphorus. The red modification is fairly stable and sublimes with a vapour pressure of 1 atmosphere at 417°C.

Pt - Platinum

This precious transition metal has been used since antiquity in South America. Spanish soldiers introduced the metal to Europe in 1750. Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda-lime-silica glass, and is therefore used to make sealed electrodes in glass systems. The metal does not oxidise in air. It is insoluble in hydrochloric and nitric acid, but dissolves when they are mixed as aqua regia, forming chloroplatinic acid (H2PtCl6), an important compound. It is corroded by halogens, cyanides, sulphur and alkalis. Hydrogen and oxygen gas mixtures explode in the presence of platinum wire.

Pb - Lead

A toxic heavy metal. Its malleability has been lead's greatest virtue as it has been used since ancient times for containers and water pipes. Lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. Lead is a bluish-white lustrous metal. It is very soft, highly malleable, ductile, and a relatively poor conductor of electricity. It is very resistant to corrosion but tarnishes upon exposure to air. Alloys include pewter and solder. Tetraethyl lead (PbEt4) is still used in some grades of petrol (gasoline) but is being phased out on environmental grounds. Lead isotopes are the end products of each of the three series of naturally occurring radioactive elements.

Po - Polonium

Discovered by Marie Curie in 1898 in Paris. Polonium has more isotopes than any other element, all of which are radioactive. Polonium dissolves readily in dilute acids, but is only slightly soluble in alkalis. Weight for weight it is about 2.5 x 1011 times as toxic as hydrocyanic acid (HCN). Polonium has been found in tobacco as a contaminant and in uranium ores.

Pr - Praseodymium

Baron von Welsbach separated the components of dydimium into neodumium (the new twin) and praseodymium (the green twin) in 1885 in Vienna. Praseodymium is soft, silvery, malleable, and ductile. It was prepared in relatively pure form in 1931. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that "spalls" away when exposed to air. The metal should be stored under an inert atmosphere or under mineral oil or petroleum. The rare-earth oxides, including Pr2O3, are among the most refractory substances known. It is a component of misch metal, used for lighter flints, and of the glass in welders' goggles.

Pm - Promethium

Promethium was found in minerals in 1926 by Harris and Hopkins in the US and independantly by Rolla and Fernando in Italy. Synthetic promethium was produced by H. B. Law in 1941. Promethium is very rare. Great care is required while handling promethium as a consequence of its radioactivity. Promethium salts luminesce in the dark with a pale blue or greenish glow, due to their high radioactivity. Ion-exchange methods led to the preparation of about 10 g of promethium from atomic reactor fuel processing wastes in early 1963. Little is yet generally known about the properties of metallic promethium. More than 30 promethium compounds have been prepared. Promethium is a rare earth metal. It appears that there is no known Pm existing in the earth's crust.

Pa - Protactinium

Both highly radioactive and toxic, protactinium was discovered independantly by Fajans and Göhring in Germany and by Soddy, Cranston and Fleck, in Scotland in 1913. The name means 'precursor of actinium'. Protactinium has a bright metallic lustre which it retains for some time in air. The element is superconductive below 1.4 K. The element is a dangerous toxic material and requires precautions similar to those used when handling plutonium. Protactinium is one of the rarest and most expensive naturally occurring elements. The element is an a-emitter and is a radiological hazard similar to polonium. Protactinium is a highly toxic and radioactive rare earth metal that requires special handling. It is found in pitchblende and ores form Zaire and is one of the rarest and most expensive naturally occurring elements.

Pu - Plutonium

Plutonium was discovered, secretly, in 1940 by Glenn Seaborg with Wahl and Kennedy at Berkeley and publicly reported in 1946. Plutonium was extracted from uranium ore in 1947. Until recently the major use of plutonium has been for nuclear weaponry, it now finds its best use in deep space probe electricity sources . The isotope 233Pu was used in the American Apollo lunar missions to power seismic and other equipment on the lunar surface. Plutonium was the second transuranium element of the actinide series to be discovered. By far of greatest importance is the isotope 239Pu, which has a half-life of more than 20000 years. One kilogram is equivalent to about 22 million kilowatt hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20000 tons of chemical explosive. The various nuclear applications of plutonium are well known. Plutonium contamination is an emotive environmental problem.

Rb - Rubidium

Discovered spectroscopically in 1861 by Robert Bunsen and Kirchoff in Heidelberg, Germany. Rubidium can be liquid at ambient temperature, but only on a hot day given that its melting point is about 40°C. It is a soft, silvery-white metallic element of the alkali metals group (Group 1). It is one of the most most electropositive and alkaline elements. It ignites spontaneously in air and reacts violently with water, setting fire to the liberated hydrogen. As so with all the other alkali metals, it forms amalgams with mercury. It alloys with gold, caesium, sodium, and potassium. It colours a flame yellowish-violet.

Ru - Ruthenium

Ruthenium was discovered in 1827 by Osann in Russia. Ruthenium is a hard, white metal. It does not tarnish at room temperatures, but oxidises in air at about 800°C. The metal is not attacked by hot or cold acids or aqua regia, but when potassium chlorate is added to the solution, it oxidises explosively.

Rh - Rhodium

This transition element was discovered in 1803 by Wollaston in London. Rhodium metal is silvery white,with a higher melting point and lower density than platinum. It has a high reflectance and is hard and durable. Upon heating it turns to the oxide when red and at higher temperatures turns back to the element. It is a major component of industrial catalytic systems such as the BP-Monsanto process.

Re - Rhenium

A very dense transition metal, discovered in 1925 by Noddack, Tacke and Berg in Germany. Rhenium is silvery white with a metallic lustre; its density is exceeded only by that of platinum, iridium, and osmium, and its melting point is exceeded only by that of tungsten and carbon. It has other useful properties. It is expensive but useful as a trace alloying agent.

Rn - Radon

Radon is a radioactive noble gas. Discovered by Dorn in 1900 in Germany. At ordinary temperatures radon is a colourless gas. When cooled below the freezing point, radon exhibits a brilliant phosphorescence which becomes yellow as the temperature is lowered and orange-red at the temperature of liquid air. The main hazard is from inhalation of the element and its decay products which are collected on dust in the air. Recently, radon buildup in homes from the surrounding soil and rocks has become a safety issue and some areas around the world test homes for radon gas. It is the heaviest known gas. Radon is present in some spring waters.

Ra - Radium

Radium metal was isolated by the Curies and Andre Debierne in 1898 in Paris.Pure metallic radium is brilliant white when freshly prepared, but blackens on exposure to air, probably due to formation of the nitride. It exhibits luminescence, as do its salts; it decomposes in water and is somewhat more volatile than barium. Radium imparts a carmine red colour to a flame. Radium emits a, b, and g rays and when mixed with beryllium produces neutrons. Inhalation, injection, or body exposure to radium can cause cancer and other body disorders. alkaline earth metal, white but tarnishes black upon exposure to air, luminesces, decomposes in water, emits radioactive radon gas, disintegrated radioactively until it reaches stable lead, radiological hazard, a, b, and g emitter, exposure to radium can cause cancer and other body disorders. Radium is over a million times more radioactive than the same mass of uranium.

Rf - Rutherfordium

This artifical element, named after Ernest Rutherford, was discovered by Ghiorso and co-workers.Rutherfordium is a synthetic element that is not present in the environment at all. It has no uses. Only very small amounts of of element 104, rutherfordium, have ever been made. The first samples were made through nuclear reactions involving fusion of an isotope of plutonium, 242Pu, with one of neon, 22Ne. 22Ne + 242Pu 260104Rf + 4 1n. Isolation of an observable quantity of rutherfordium has never been achieved.

Si - Silicon

Silicon is the quintesential metalloid. Pure silicon is used for electronic devices, but the oxide and silicate minerals comprise more than a quarter of the earth's crust. Jöns Berzelius isolated silicon in 1823 in Stockholm by potassium fusion of quartz. Silicon is present in the sun and stars and is a principal component of a class of meteorites known as aerolites. Silicon makes up 25.7% of the earth's crust by weight, and is the second most abundant element, exceeded only by oxygen. It is found largely as silicon oxides such as sand (silica), quartz, rock crystal, amethyst, agate, flint, jasper and opal. Silicon is found also in minerals such as asbestos, feldspar, clay and mica. Silicon is important in plant and animal life. Diatoms in both fresh and salt water extract silica from the water to use as a component of their cell walls. Silicon is an important ingredient in steel. Silicon carbide is one of the most important abrasives. Workers in environments where silicaceous dust is breathed may develop a serious lung disease known as silicosis. Hydrolysis and condensation of substituted chlorosilanes can be used to produce a very great number of polymeric products, or silicones. These range from liquids to hard, glasslike solids with many useful properties. Elemental silicon transmits more than 95% of all wavelengths of infrared and and has been used in lasers to produce coherent light at 456 nm.

S - Sulfur

This yellow non-metal has been known through the ages. The spelling of sulphur is "sulfur" in the USA and now that IUPAC (International Union of Pure and Applied Chemistry) has decided it has jurisdiction over the English language as well as nomenclature, we in the UK are expected to use the f word. Sulphur is found in meteorites, volcanoes, hot springs, and as galena, gypsum, Epsom salts, and barite. It is recovered commercially from "salt domes" along the Gulf Coast of the USA. Jupiter's moon Io owes its colours to various forms of sulphur. A dark area near the crater Aristarchus on the moon may be a sulphur deposit.

Sc - Scandium

Scandium was discovered in 1879 by Nilson in Sweden. Scandium is apparently a much more abundant element in the sun and certain stars than on earth. Scandium is a silvery-white metal which develops a slightly yellowish or pinkish cast upon exposure to air. It is relatively soft, and resembles yttrium and the rare-earth metals more than it resembles aluminium or titanium. Scandium reacts rapidly with many acids.

Se - Selenium

Selenium was discovered by J. J. Berzelius in 1817 in Sweden. Selenium can be prepared with either an amorphous or crystalline structure. Crystalline monoclinic selenium is deep red; crystalline hexagonal selenium, the most stable variety, is a metallic grey . Elemental selenium is relatively nontoxic and is considered to be an essential trace element. However, hydrogen selenide (H2Se) and other selenium compounds are extremely toxic, and resemble arsenic in their physiological reactions. Hydrogen selenide in a concentration of 1.5 ppm is intolerable to man. Selenium occurs in some soils in amounts sufficient to produce serious effects on animals feeding on plants such as locoweed (an American plant) grown in such soils.

Sr - Strontium

An alkaline earth metal. Discovered in 1790 by Crawford in Scotland, and obtained as a metal by Davy in 1807 in London. Strontium does not occur as the free element. Strontium is softer than calcium and decomposes water more vigorously. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish colour with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart an excellent crimson colour to flames, and these salts are used in pyrotechnics.

Sn - Tin

A metal known to the ancients. Ordinary tin is a silvery-white metal, is malleable, somewhat ductile, and has a highly crystalline structure. Due to the breaking of these crystals, a "tin cry" is heard when a bar is bent. The element has two allotropic forms. On warming, grey, or a-tin, with a cubic structure, changes at 13.2°C into white, or b-tin, the ordinary form of the metal. White tin has a tetragonal structure. When tin is cooled below 13.2°C, it changes slowly from white to grey. This change is affected by impurities such as aluminium and zinc, and can be prevented by small additions of antimony or bismuth. The conversion was first noted as growths on organ pipes in European cathedrals, where it was thought to be the devils work. This conversion was also speculated to be caused by microorganisms and was called "tin plague" or "tin disease". Tin resists distilled, sea, and soft tap water, but is attacked by strong acids, alkalis, and acid salts. Oxygen in solution accelerates the attack. When heated in air, tin forms SnO2. It is, or was, used to plate steel, making "tin cans". Tin is used as one component in bell metals.

Sb - Antimony

A semi-metal. Metallic antimony is an extremely brittle metal of a flaky, crystalline texture. It is bluish white and has a metallic lustre. It is not acted on by air at room temperature, but burns brilliantly when heated with the formation of white fumes. It is a poor conductor of heat and electricity. Antimony and its compounds are toxic. It is found mostly with other minerals and in stibnite.

Sg - Seaborgium

An artifical element named after Glenn Seaborg. Discovered by Ghiorso, etal. Seaborgium is a synthetic element that is not present in the environment at all. It has no uses.

Sm - Samarium

Samarium was discovered by Lecoq de Boisbaudrain in 1879 in Paris. Samarium has a bright silver lustre and is reasonably stable in air. It ignites in air at 150°C. It is a rare earth metal. It is found with other rare earth elements in minerals including monazite and bastnaesite and is used in electronics industries.

Ti - Titanium

A transition metal. Discovered in the mineral manaccanite in 1791 by William Gregor in England. Isolated in 1875 by Kirillov in Russia. Titanium, when pure, is a lustrous, white metal. Titanium minerals are quite common. The metal has a low density, good strength, is easily fabricated, and has excellent corrosion resistance. The metal burns in air and is the only element that burns in nitrogen. It is marvellous in fireworks.

Tc - Technetium

Technetium was discovered platinum ore from Columbia using x-ray spectroscopy by Walter Noddack and Ida Tacke in Berlin. The element was artificially produced in 1937 by Emilio Segrè and Carlo Perrier in Berkeley. Technetium is used for medical scintigraphic imaging. Since its discovery, searches for the element technetium in terrestrial materials have been made without success. Technetium has been found in the spectrum of S-, M-, and N-type stars, and its presence in stellar matter is leading to new theories of the production of heavy elements in the stars. Technetium is a silvery-grey metal that tarnishes slowly in moist air. Until 1960, technetium was available only in small amounts. The chemistry of technetium is related to that of rhenium.

Te - Tellurium

A metallic appearing metaloid, tellurium was discovered in 1782 by Baron von Reichenstein in Romania. Crystalline tellurium has a silvery-white appearance, and exhibits a metallic lustre when pure. It is brittle and easily pulverised. Tellurium is a p-type semiconductor, and shows varying conductivity with crystal alignment. Its conductivity increases slightly with exposure to light. It can be doped with silver, copper, gold, tin, or other elements. Humans exposed to as little as 0.01 mg m-3 in air, or less, develop "tellurium breath", which has a garlic-like odour.

Ta - Tantalum

Tantalum, the third member of the acid earth family, is a hard metal with reactivity lower even than platinium. The 'element' columbium was discovered in columbite minerals from Connecticut by Charles Hatchett in 1801. Columbium however was shown to be two metals one of which was was tantalum. (The other was niobium.) Tantalum oxide was isolated by Anders G. Ekeberg in 1802 who then named the element because it tantalized his efforts to purify the metal. The pure metal was finally obtained, electrochemically, by Bolton in 1905.

Tl - Thallium

The toxic heavy metal thallium was discovered in 1861 by Crookes in London. When freshly exposed to air, thallium exhibits a metallic lustre, but soon develops a bluish-grey tinge, resembling lead in appearance. A heavy oxide builds up on thallium if left in air, and in the presence of water the hydroxide is formed. The metal is very soft and malleable. It can be cut with a knife. The element and its compounds are toxic and should be handled carefully. Thallium may cause cancer.

Tb - Terbium

Terbium was discovered by Mosander in 1843 in Stockholm. One of four elements named for the Swedish town of Ytterby. Terbium is reasonably stable in air. It is a silvery-grey metal, and is malleable, ductile, and soft enough to be cut with a knife. It is a rare earth metal found in cerite, gadolinite and monazite. The element itself was isolated only recently.

Tm - Thulium

Thulium was discovered in erbium ore in 1879 by Per Cleve in Sweden. Thulium is the least abundant of the earth elements, and is about as rare as silver, gold, or cadmium. The pure metal has a bright, silvery lustre. It is reasonably stable in air, but the metal must be protected from moisture. The element is silvery-grey, soft, malleable, and ductile, and can be cut with a knife. It is a rare earth metal found in minerals such as monazite.

Th - Thorium

A long halflife radioactive metal, thorium was identified in 1821and isolated by J. J. Berzelius in 1828 in Sweden, and named after Thor, the Scandinavian god of war.Thorium is used in gas lamp mantles and nuclear breeder reactors. Thorium is a source of nuclear power. There is probably more untapped energy available for use from thorium in the minerals of the earth's crust than from combined uranium and fossil fuel sources. Much of the internal heat the earth has been attributed to thorium and uranium. When pure, thorium is a silvery white metal which is air-stable and retains its lustre for several months. When contaminated with the oxide, thorium slowly tarnishes in air, becoming grey and finally black. Thorium oxide has a melting point of 3300°C, the highest of all oxides. Only a few elements, such as tungsten, and a few compounds, such as tantalum carbide, have higher melting points. Thorium is slowly attacked by water, but does not dissolve readily in most common acids, except hydrochloric. Powdered thorium metal is often pyrophoric and should be carefully handled.When heated in air, thorium turnings ignite and burn brilliantly with a white light. It is found in thorite and thorianite in New England (USA) and other sites.

U - Uranium

Uranium oxide has been used since Roman times for yellow pigments in glass. The element was discovered in 1789 by a German chemist, Martin Klaproth, who named it for the newly observed seventh planet. In 1841, French chemist Eugene Peligot extracted pure uranium metal, which caused little interest until March 1, 1869, when French physicist, Henry Becquerel serendipidously discovered radioactivity in uranium salts - suddenly uranium was hot stuff!
Although only mildly radioactive, uranium compounds are toxic.

V - Vanadium

A transition metal discovered in 1801 by Andreas del Rio in Mexico. The major use of the element is in hardened steels. Pure vanadium is a greyish silvery metal, and is soft and ductile. It has good corrosion resistance to alkalis, sulphuric acid, hydrochloric acid, and salt waters. The metal oxidizes readily above 660°C to form V2O5.

W - Tungsten

Wolfram, also known as tungsten, is used for lightbulb filiments. Discovered by Swedish pharmacist Karl Scheele in 1781 in the mineral called tungsten (now known as scheelite). Spanish chemists and brothers Don Fausto, and Don Juan del Huyar extracted the pure metal from another mineral, wolframite in 1873. Pure tungsten is a steel-gray to tin-white metal. Tungsten has the highest melting point and lowest vapour pressure of all metals, and at temperatures over 1650°C has the highest tensile strength. The metal oxidises in air and must be protected at elevated temperatures. It has excellent corrosion resistance and is attacked only slightly by most mineral acids.

Xe - Xenon

Xenon from Greek's word for stranger, is a rare gas that was extracted from the atmosphere (along with neon, krypton and radon.) by William Ramsey and M. W. Travers in 1898. Xenon is a "noble" or "inert" gas present in the atmosphere to a small extent. Xenon is present in the Martian atmosphere to the extent of about 0.08 ppm. Before 1962, it was generally assumed that xenon and other noble gases were unable to form compounds. Among the compounds of xenon now reported are xenon hydrate, sodium perxenate, xenon deuterate, difluoride, tetrafluoride, hexafluoride, and XePtF6 and XeRhF6. The highly explosive xenon trioxide, XeO3, is known. Metallic xenon is produced by applying several hundred kilobars of pressure. Xenon in a vacuum tube produces a blue glow when excited by an electrical discharge and finds use in strobe lamps. It is an odourless, colourless, inert gas.

Y - Yttrium

Although a period 5 transition metal, yttrium is associated with the rare earths. J. Gadolin discovered yttria mineral in 1794, proposing it as a new metal's oxide. A mixture of the reduced metals was obtained by Wöhler in 1828. In 1843 C. G. Mosander separated yttria into oxides of three metals, which were named yttrium, erbium and terbium, as they were found in a quarry near Ytterby, Sweden. Yttrium is used in color phosphors, lasers, ceramic superconductors and has been found in relatively high concentrations in lunar samples.

Yb - Ytterbium

Ytterbium was discovered in 1878 by Jean de Marignac in Switzerland. Ytterbium has a bright silvery lustre, is soft, malleable, and quite ductile. While the element is fairly stable, it should be kept in closed containers to protect it from air and moisture. Ytterbium is readily attacked and dissolved by mineral acids and reacts slowly with water.

Zn - Zinc

Usually a grey colored transition metal, zinc was known in ancient Asia and early Europe. It can be easilly alloyed with copper and other metals and so has found wide metalurgical use. Lately zinc gluconate has become popular as a cold remedy. Zinc is a bluish-white, lustrous metal. It is brittle at ambient temperatures but is malleable at 100 to 150°C. It is a reasonable conductor of electricity, and burns in air at high red heat with evolution of white clouds of the oxide.

Zr - Zirconium

Zirconium was discovered in 1789 by Martin Klaproth working in Berlin and the pure metal obtained by Berzelius in 1824 in Stockholm. Zirconium is a greyish-white lustrous metal. The finely divided metal can ignite spontaneously in air, especially at elevated temperatures. The solid metal is much more difficult to ignite. The inherent toxicity of zirconium compounds is low. Hafnium is invariably found in zirconium ores, and the separation is difficult. Commercial grade zirconium contains from 1 to 3% hafnium. The hafnium is removed from the zirconium, and the hafnium free zirconium is used to contain nuclear fuel in reactors.

"What weapon can you make from the Chemicals Potassium, Nickel and Iron? - a KNiFe".