[erickejah]

Rubidium and Caesium in water:

I wonder how much Caesium cost??

[Chemistry4me]

Have a look here

[Chemistry4me]

Gadolinium, silvery-white metallic element. Gadolinium is one of the rare earth elements in the lanthanide series of the periodic table. Gadolinium occurs with other rare earth elements in many minerals, such as samarskite, gadolinite, monazite, and some varieties of Norwegian ytterspar. It is the 41st element in order of abundance in the crust of the Earth. Gadolinium oxide was first separated from other rare earth elements by the Swiss chemist Jean de Marignac in 1880. The oxide and many salts of gadolinium have been prepared. Gadolinium oxide is white and the salts are colourless. Because gadolinium has the largest known cross section, or stopping power, for neutrons of any element, it is used as a component of control rods in nuclear reactors. Like the other rare earth elements, it is used in electronic apparatus such as capacitors and masers; in metal alloys; in high-temperature furnaces; and in apparatus for magnetic cooling.

[Chemistry4me]

Terbium is one of the rare earth elements in the lanthanide series of the periodic table. It ranks about 58th in natural abundance among the elements in crustal rock. It occurs in minute quantities as a white oxide known as terbia, Tb2O3, in such minerals as gadolinite. Terbium has potential applications in alloys, refractory (high-temperature) materials, and electronic apparatus.

[Chemistry4me]

Dysprosium, metallic element. Dysprosium is one of the rare earth elements in the lanthanide series of the periodic table. Dysprosium is 42nd in abundance among the elements in the Earth's crust. The compounds of dysprosium are found in gadolinite, xenotime, euxenite, and fergusonite in Norway, the United States, Brazil, India, and Australia. Its salts are either yellow or yellow-green in colour, the most common being a chloride (DyCl3), a nitrate (Dy(NO3)3•5H2O), and a sulphate (Dy2(SO4)3•8H2O). The salts of dysprosium have an extremely high magnetic susceptibility. Dysprosium usually occurs as the white oxide dysprosia (Dy2O3), with erbium and holmium, two other rare earth elements. Dysprosia is sometimes used in the control rods of nuclear reactors

[Chemistry4me]

Holmium, silver-coloured metallic element. Holmium is one of the most paramagnetic substances known. The element has few practical applications, though it has been used in some electronic devices and as a catalyst in industrial chemical reactions. Holmium is one of the least abundant of the rare earth metals, ranking 55th in order of abundance of the elements in the Earth's crust. Holmium occurs in gadolinite and other minerals containing rare earths. Holmium oxide, Ho2O3, a greyish-white powder, and a few salts, such as the sulphate, have been prepared.

[Chemistry4me]

Erbium, metallic element. The Swedish chemist Carl Gustav Mosander discovered erbium in 1843. Erbium occurs mostly in the same minerals and in the same areas as dysprosium. One of the rare earth elements, erbium is 43rd in abundance among the elements of the Earth's crust. The atomic weight of erbium is 167.26. The element melts at about 1530°C , boils at about 2870°C , and has a relative density of 9.1. Metallic erbium has a bright silvery lustre. Erbium oxide, Er2O3, is a rose-red compound slowly soluble in many mineral acids, forming a series of rose-coloured salts, solutions of which have a sweet, astringent taste. Erbium is used in experimental optical amplifiers that amplify light signals sent along fibre-optic cables

[Chemistry4me]

Thulium, silver-grey metallic element that is the rarest of the rare earth elements. Thulium is in the lanthanide series of the periodic table the atomic number of thulium is 69. Thulim was discovered in 1879 by the Swedish chemist Per Teodor Cleve. Thulium ranks 61st in abundance among the elements in the crust of the Earth and is found in small quantities in such rare earth minerals as euxenite, gadolinite, and blomstrandine. The metal can be isolated by reduction of its oxide, Tm2O3, and is soft, malleable, and ductile. Thulium had little practical application until the development in the 1950s of a small, portable X-ray machine that utilizes artificially radioactive thulium as its X-ray source. Thulium melts at about 1545°C, boils at about 1950°C, and has a relative density of 9.34.

[Chemistry4me]

Ytterbium, soft, malleable, ductile metallic element that has a bright, silvery lustre. Ytterbium is one of the rare earth elements in the lanthanide series of the periodic table. Ytterbium is reasonably stable but reacts slowly with water to liberate hydrogen. Ytterbium occurs in combination with such minerals as xenotime, euxenite, monazite, and gadolinite. It ranks about 44th in natural abundance among the elements in the Earth's crust. Ytterbium has potential applications in alloys, electronics, and magnetic materials.

[Chemistry4me]

Lutetium, silvery-white metallic element with an atomic number of 71. Lutetium was discovered independently by two investigators, the French chemist Georges Urbain in 1907 and the Austrian chemist Carl Auer von Welsbach about the same time. It was named by Urbain, who derived the word from Lutetia, the ancient name of Paris. Lutetium occurs in various rare earth minerals, usually associated with yttrium. It was the rarest of the rare earth elements when classified in that group and it ranks 59th in order of abundance of the elements in the Earth's crust. Several trivalent salts are known. A natural radioactive isotope of lutetium that has a half-life of about 30 billion years is used in determining the age of meteorites in relation to the age of the Earth. Lutetium melts at about 1665°C, boils at about 3400°C and has a relative density of 9.84.

[Chemistry4me]

Hafnium, metallic element that closely resembles zirconium. Hafnium is one of the transition elements of the periodic table. On the basis of a prediction by the Danish physicist Niels Bohr that element 72 would resemble zirconium in structure, they looked for the element in zirconium ores. Hafnium is found in nearly all ores of zirconium and is 45th in order of abundance of the elements in the crust of the Earth. It resembles zirconium so closely in chemical properties and crystal structure that separation of the two elements is extremely difficult. Separation is accomplished most efficiently by means of the ion-exchange technique. Hafnium is used in the manufacture of tungsten filaments. Because of its resistance to high temperatures, it is used with zirconium as a structural material in nuclear power plants.

[Chemistry4me]

Tantalum, white, ductile, malleable metallic element. Tantalum is one of the transition elements of the periodic table. Tantalum belongs to the group of metals that includes vanadium and niobium. It occurs mainly in the mineral tantalite, FeTa2O6. Tantalum ranks about 53rd among the elements in natural abundance in the Earth's crust. Principal deposits of the metal occur in Australia and Scandinavia. Most tantalum minerals contain some niobium metal, which is separated by solvent extraction or selective-crystallization procedures. Commercially, tantalum is prepared by the electrolysis of fused potassium tantalifluoride or of tantalum compounds dissolved in dilute sulphuric acid. Because it is more resistant than platinum to many corrosive agents, tantalum has largely replaced platinum in standard weights and in laboratory ware. The largest use of tantalum is for capacitors in electronic circuits and rectifiers in low-voltage circuits, such as railway-signalling systems. Because of its resistance to attack by acids of the human body and its compatibility with body tissue, it is used to pin together broken bones. Tantalum is also used in surgical and dental instruments and in chemical heat exchangers. The oxide is an ingredient in special optical glass for aerial camera lenses.

[Chemistry4me]

Tungsten, symbol W (from the earlier name, wolfram), metallic element that has the highest melting point of any metal. Tungsten is one of the transition elements of the periodic table. Pure tungsten is silver-white in colour and is ductile; the more easily obtained impure form is steel-grey and is hard and brittle. Tungsten is insoluble in hot and cold water and in alcohol, slightly soluble in ammonia and nitric acid, and soluble in hot, concentrated potassium hydroxide. Tungsten ranks 57th in abundance among the elements in the crust of the Earth. It is never found free in nature, but occurs in combination with other metals, notably in the minerals scheelite and wolframite, which are the important tungsten ores. Mines in South Korea, Portugal, Austria, and Australia produce more than half of the world's supply of these ores. To separate the element from its ore, the ore is first fused with sodium carbonate to give sodium tungstate, Na2WO4. The soluble sodium tungstate is then extracted with hot water and treated with hydrochloric acid to yield tungstic acid, H2WO4. The latter compound is washed and dried to produce the oxide WO3, which is reduced by hydrogen in an electric furnace. The resulting fine powder is reheated in moulds in an atmosphere of hydrogen and pressed into bars, which are hammered and rolled at high temperature to compact them and make them ductile. The principal uses of tungsten are as filaments in incandescent lamps, as wires in electric furnaces, and in the production of hard, tenacious alloys of steel. It is used also in the manufacture of spark plugs, electrical contact points, and cutting tools, and as a target in X-ray tubes.

[Chemistry4me]

Rhenium, rare, silvery-white, metallic element. Rhenium is one of the transition elements of the periodic table. The existence of rhenium and the similarity of its chemical properties to those of the element manganese were predicted in 1871 by the Russian chemist Dmitry Ivanovich Mendeleyev, who named it dvi-manganese. Rhenium metal is very hard; with the exception of tungsten, it is the least fusible of all common metals. Overall, it ranks about 79th in natural abundance among elements in crustal rocks. Rhenium is used in electrical filaments, welding rods, thermocouples, cryogenic magnets, and photographic flashbulb filaments; it is also used as a catalyst.

[Chemistry4me]

Osmium, bluish-white, brittle metallic element that has a density second only to iridium (although uncertainty has been expressed as to this and claims have been made for osmium having the highest relative density). The element is one of the transition elements of the periodic table. Osmium is not attacked by ordinary acids, but dissolves in aqua regia or fuming nitric acid. The metal occurs naturally in platinum ores and as an alloy, osmiridium, with iridium. Osmium ranks about 74th in natural abundance among the elements in crustal rock. The chief use of the metal is in the alloy osmiridium. Alloyed with platinum, it is used for standard weights and measures.

[Chemistry4me]

Iridium, white, brittle, extremely hard, metallic element. Iridium is extremely inert chemically, resisting even the action of aqua regia. In its chemical compounds it forms tetravalent and trivalent salts. It is an extremely rare metal, ranking 77th in order of abundance of the elements in the crust of the Earth. Iridium is found in alluvial deposits alloyed with platinum as platiniridium and with osmium as osmiridium. Iridium is used chiefly as an alloying material for platinum; the alloy, which contains about 10 per cent iridium, is much harder than pure platinum. Platinum-iridium alloys containing larger percentages of iridium are used in making precision instruments, surgical tools, pen points, and standard weights and lengths. Iridium was discovered by the British chemist Smithson Tennant in 1804 and was named after the iridescent nature of some of its compounds.

[Chemistry4me]

Platinum, relatively rare, chemically inert metallic element that is more valuable than gold. The element is one of the transition elements in group 10 of the periodic table. Platinum is a greyish-white metal with a hardness of 4.3. It has a high fusing point, is malleable and ductile, expands slightly upon heating, and has high electrical resistance. Chemically the metal is relatively inert and resists attack by air, water, single acids, and ordinary reagents. It dissolves slowly in aqua regia, forming chloroplatinic acid (H2PtCl6); is attacked by halogens; and combines upon ignition with sodium hydroxide, sodium nitrate, or sodium cyanide. Platinum ranks about 72nd in natural abundance among the elements in crustal rock. Except for the mineral sperrylite, which is platinum arsenide and is found only sparingly in a few localities, platinum occurs in the metallic state, often alloyed with other platinum metals. Nuggets of the metal weighing up to 9.5 kg have been found. Because of its chemical inertness and high fusing point, platinum is valuable for laboratory apparatus, such as crucibles, tongs, funnels, combustion boats, and evaporating dishes. Small amounts of iridium are usually added to increase its hardness and durability. Platinum is also used for contact points in electrical apparatus and in instruments used for measuring high temperatures. Finely divided platinum in the form of platinum sponge or platinum black is used extensively as a catalyst in the chemical industry. A considerable amount of platinum goes into jewellery, in which it is often alloyed with gold. It is also used for dental fillings.

[Chemistry4me]

Gold, Au, (from Latin aurum, “gold”), soft, dense, bright yellow metallic element. Pure gold is the most malleable and ductile of all the metals. It can easily be beaten or hammered to a thickness of 0.000013 cm, and 29 g could be drawn into a wire 100 km long. It is one of the softest metals (hardness, 2.5 to 3) and is a good conductor of heat and electricity. Finely divided gold, like other metallic powders, is black; colloidally suspended gold ranges in colour from ruby red to purple. Gold is extremely inactive. It is unaffected by air, heat, moisture, and most solvents. It will, however, dissolve in aqueous mixtures containing various halogens such as chlorides, bromides, or some iodides. It will also dissolve in some oxidizing mixtures, such as cyanide ion with oxygen, and in aqua regia, a mixture of hydrochloric and nitric acids. Gold is found in nature in quartz veins or seams, nuggets, flakes, and secondary alluvial deposits as a free metal or in a combined state. There are several chemical and physical processes that may cause these formations, and it is also likely that colonies of soil bacteria and fungi play a part in gold agglomerations. Gold is widely distributed although it is rare, being 75th in order of abundance of the elements in the crust of the Earth. It is almost always associated with varying amounts of silver; the naturally occurring gold-silver alloy is called electrum. Gold occurs, in chemical combination with tellurium, in the minerals calaverite and sylvanite along with silver, and in the mineral nagyagite along with lead, antimony, and sulphur. It occurs with mercury as gold amalgam. It is generally present to a small extent in iron pyrites; galena, the lead sulphide ore that usually contains silver, sometimes also contains appreciable amounts of gold. Gold also occurs in sea water to the extent of 5 to 250 parts by weight to 100 million parts of water. Although the quantity of gold present in sea water is more than 9 billion tonnes, the cost of recovering the gold would be far greater than the value of the gold that could thus be recovered. The major portion of the gold produced is used in coinage and jewellery. For these purposes it is alloyed with other metals to give it the necessary hardness. The gold content in alloys is expressed in carats. Coinage gold is composed of 90 parts gold to 10 parts silver. Green gold used in jewellery contains copper and silver; white gold contains zinc and nickel, or platinum metals. Gold is also used in dentistry. Radioisotopes of gold are used in biological research and in the treatment of cancer.

[Chemistry4me]

Mercury, (Latin, hydrargyrum, “liquid silver”), metallic element that is a free-flowing liquid at room temperature. Mercury, once known as liquid silver and as quicksilver, was studied in alchemy. At ordinary temperatures mercury is a shining, mobile liquid, silvery-white in colour. Slightly volatile at room temperature, mercury becomes solid when subjected to a pressure of 7,640 atmospheres (5.8 million torrs), and this pressure is used as a standard in measuring extremely high pressures. The metal dissolves in nitric or concentrated sulphuric acid but is resistant to alkalis. Mercury is acutely hazardous as a vapour and in the form of its water-soluble salts, which corrode membranes of the body. Chronic mercury poisoning, which occurs when small amounts of the metal or its fat-soluble salts, particularly methylmercury, are repeatedly ingested over long periods of time, causes irreversible brain, liver, and kidney damage. Because of increasing water pollution, significant quantities of mercury have been found in some species of fish, which has aroused concern regarding uncontrolled discharge of the metal into the environment.

[Chemistry4me]

Thallium (Greek, thallos, “young shoot”), soft, malleable metallic element that acquires a bluish-grey colour upon exposure to the atmosphere. Thallium forms a hydroxide in water, and is soluble in nitric acid and sulphuric acid. Thallous oxide, Tl2O, a black solid that, when molten, attacks glass and porcelain, is made by heating thallium in air at very high temperatures. Thallium has a high index of refraction and is therefore important in the manufacture of several types of optical glass. Thallium ranks 60th in abundance among the elements in the crust of the Earth and is a member of the aluminium family of metals. Thallium sulphate, which is odourless, tasteless, and very poisonous, is used to exterminate rodents and ants. Thallium-activated sodium iodide crystals mounted in photomultiplier tubes are used in some portable scintillation counters to detect gamma radiation. The abilities of thallium bromoiodide crystals to transmit infrared radiation and of thallium oxysulphide crystals to detect the same radiation have been employed extensively in military communication systems. Thallium alloyed with mercury forms a fluid metal that freezes at -60°C; it is used in low-temperature thermometers, relays, and switches. Thallium salts, which burn with a bright green flame, are used in rockets and flares.