types:
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allotrope
a structurally different form of an element
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transuranic element
any element having an atomic number greater than 92 (which is the atomic number of uranium); all are radioactive
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argonon, inert gas, noble gas
any of the chemically inert gaseous elements of the helium group in the periodic table
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metal, metallic element
any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
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nonmetal
a chemical element lacking typical metallic properties
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transactinide
any of the artificially produced elements with atomic numbers greater than 103
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Ac, actinium, atomic number 89
a radioactive element of the actinide series; found in uranium ores
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Ar, argon, atomic number 18
a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
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As, arsenic, atomic number 33
a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
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At, astatine, atomic number 85
a highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium
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Bh, atomic number 107, bohrium, element 107
a transuranic element
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B, atomic number 5, boron
a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder
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Br, atomic number 35, bromine
a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens; found in sea water
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C, atomic number 6, carbon
an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
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Cl, atomic number 17, chlorine
a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)
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Ds, atomic number 110, darmstadtium, element 110
a radioactive transuranic element
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Db, atomic number 105, dubnium, element 105, hahnium
a transuranic element
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F, atomic number 9, fluorine
a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite
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Ge, atomic number 32, germanium
a brittle grey crystalline element that is a semiconducting metalloid (resembling silicon) used in transistors; occurs in germanite and argyrodite
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Hs, atomic number 108, element 108, hassium
a radioactive transuranic element
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He, atomic number 2, helium
a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
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H, atomic number 1, hydrogen
a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
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I, atomic number 53, iodin, iodine
a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)
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Kr, atomic number 36, krypton
a colorless element that is one of the six inert gasses; occurs in trace amounts in air
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Lr, atomic number 103, lawrencium
a radioactive transuranic element synthesized from californium
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Mt, atomic number 109, element 109, meitnerium
a radioactive transuranic element
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Md, Mv, atomic number 101, mendelevium
a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol)
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Ne, atomic number 10, neon
a colorless odorless gaseous element that give a red glow in a vacuum tube; one of the six inert gasses; occurs in the air in small amounts
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N, atomic number 7, nitrogen
a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues
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No, atomic number 102, nobelium
a radioactive transuranic element synthesized by bombarding curium with carbon ions; 7 isotopes are known
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O, atomic number 8, oxygen
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
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P, atomic number 15, phosphorus
a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms
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Pu, atomic number 94, plutonium
a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239
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Rn, atomic number 86, radon
a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health
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Rg, atomic number 111, element 111, roentgenium
a radioactive transuranic element
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Rf, Unq, atomic number 104, element 104, rutherfordium, unnilquadium
a radioactive transuranic element which has been synthesized
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Sg, atomic number 106, element 106, seaborgium
a transuranic element
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Se, atomic number 34, selenium
a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite)
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Si, atomic number 14, silicon
a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
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S, atomic number 16, sulfur, sulphur
an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
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Te, atomic number 52, tellurium
a brittle silver-white metalloid element that is related to selenium and sulfur; it is used in alloys and as a semiconductor; occurs mainly as tellurides in ores of copper and nickel and silver and gold
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Uub, atomic number 112, element 112, ununbium
a radioactive transuranic element
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Uuh, atomic number 116, element 116, ununhexium
a radioactive transuranic element
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Uup, atomic number 115, element 115, ununpentium
a radioactive transuranic element
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Uuq, atomic number 114, element 114, ununquadium
a radioactive transuranic element
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Uut, atomic number 113, element 113, ununtrium
a radioactive transuranic element
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Xe, atomic number 54, xenon
a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
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trace element
an element that occurs at very small quantities in the body but is nonetheless important for many biological processes
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metalloid
a nonmetallic element that has some of the properties of metal
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tritium
a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms
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heavy metal
a metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead)
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base metal
a metal that is common and not considered precious
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fullerene
a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms
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noble metal
any metal that is resistant to corrosion or oxidation
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Al, aluminium, aluminum, atomic number 13
a silvery ductile metallic element found primarily in bauxite
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Am, americium, atomic number 95
a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms
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Sb, antimony, atomic number 51
a metallic element having four allotropic forms; used in a wide variety of alloys; found in stibnite
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Ar, argon, atomic number 18
a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
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Ba, atomic number 56, barium
a soft silvery metallic element of the alkali earth group; found in barite
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Bk, atomic number 97, berkelium
a radioactive transuranic element; discovered by bombarding americium with helium
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Be, atomic number 4, beryllium, glucinium
a light strong brittle grey toxic bivalent metallic element
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Bi, atomic number 83, bismuth
a heavy brittle diamagnetic trivalent metallic element (resembles arsenic and antimony chemically); usually recovered as a by-product from ores of other metals
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Cd, atomic number 48, cadmium
a soft bluish-white ductile malleable toxic bivalent metallic element; occurs in association with zinc ores
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Ca, atomic number 20, calcium
a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals
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Cf, atomic number 98, californium
a radioactive transuranic element; discovered by bombarding curium with alpha particles
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carbon 14, radiocarbon
a radioactive isotope of carbon
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Ce, atomic number 58, cerium
a ductile grey metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group
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Cs, atomic number 55, caesium, cesium
a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal
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radiochlorine
a radioactive isotope of chlorine
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Cr, atomic number 24, chromium
a hard brittle multivalent metallic element; resistant to corrosion and tarnishing
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Co, atomic number 27, cobalt
a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
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Cu, atomic number 29, copper
a ductile malleable reddish-brown corrosion-resistant diamagnetic metallic element; occurs in various minerals but is the only metal that occurs abundantly in large masses; used as an electrical and thermal conductor
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Cm, atomic number 96, curium
a radioactive transuranic metallic element; produced by bombarding plutonium with helium nuclei
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Dy, atomic number 66, dysprosium
a trivalent metallic element of the rare earth group; forms compounds that are highly magnetic
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E, Es, atomic number 99, einsteinium
a radioactive transuranic element produced by bombarding plutonium with neutrons
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Er, atomic number 68, erbium
a trivalent metallic element of the rare earth group; occurs with yttrium
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Eu, atomic number 63, europium
a bivalent and trivalent metallic element of the rare earth group
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Fm, atomic number 100, fermium
a radioactive transuranic metallic element produced by bombarding plutonium with neutrons
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Fr, atomic number 87, francium
a radioactive element of the alkali-metal group discovered as a disintegration product of actinium
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Gd, atomic number 64, gadolinium
a ductile silvery-white ductile ferromagnetic trivalent metallic element of the rare earth group
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Ga, atomic number 31, gallium
a rare silvery (usually trivalent) metallic element; brittle at low temperatures but liquid above room temperature; occurs in trace amounts in bauxite and zinc ores
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Hf, atomic number 72, hafnium
a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons
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He, atomic number 2, helium
a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
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Ho, atomic number 67, holmium
a trivalent metallic element of the rare earth group; occurs together with yttrium; forms highly magnetic compounds
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In, atomic number 49, indium
a rare soft silvery metallic element; occurs in small quantities in sphalerite
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iodine-131
heavy radioactive isotope of iodine with a half-life of 8 days; used in a sodium salt to diagnose thyroid disease and to treat goiter
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iodine-125
light radioactive isotope of iodine with a half-life of 60 days; used as a tracer in thyroid studies and as a treatment for hyperthyroidism
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Ir, atomic number 77, iridium
a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
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Fe, atomic number 26, iron
a heavy ductile magnetic metallic element; is silver-white in pure form but readily rusts; used in construction and tools and armament; plays a role in the transport of oxygen by the blood
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Kr, atomic number 36, krypton
a colorless element that is one of the six inert gasses; occurs in trace amounts in air
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La, atomic number 57, lanthanum
a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth
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Pb, atomic number 82, lead
a soft heavy toxic malleable metallic element; bluish white when freshly cut but tarnishes readily to dull grey
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Li, atomic number 3, lithium
a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals
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Lu, atomic number 71, lutecium, lutetium
a trivalent metallic element of the rare earth group; usually occurs in association with yttrium
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Mg, atomic number 12, magnesium
a light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine)
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Mn, atomic number 25, manganese
a hard brittle grey polyvalent metallic element that resembles iron but is not magnetic; used in making steel; occurs in many minerals
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Hg, atomic number 80, hydrargyrum, mercury, quicksilver
a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures
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Mo, atomic number 42, molybdenum
a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel
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Nd, atomic number 60, neodymium
a yellow trivalent metallic element of the rare earth group; occurs in monazite and bastnasite in association with cerium and lanthanum and praseodymium
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Ne, atomic number 10, neon
a colorless odorless gaseous element that give a red glow in a vacuum tube; one of the six inert gasses; occurs in the air in small amounts
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Np, atomic number 93, neptunium
a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium
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Ni, atomic number 28, nickel
a hard malleable ductile silvery metallic element that is resistant to corrosion; used in alloys; occurs in pentlandite and smaltite and garnierite and millerite
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Nb, atomic number 41, niobium
a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
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azote
an obsolete name for nitrogen
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Os, atomic number 76, osmium
a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
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LOX, liquid oxygen
a bluish translucent magnetic liquid obtained by compressing gaseous oxygen and then cooling it below its boiling point; used as an oxidizer in rocket propellants
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Pd, atomic number 46, palladium
a silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry
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plutonium 239
a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons
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Po, atomic number 84, polonium
a radioactive metallic element that is similar to tellurium and bismuth; occurs in uranium ores but can be produced by bombarding bismuth with neutrons in a nuclear reactor
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K, atomic number 19, potassium
a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
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Pr, atomic number 59, praseodymium
a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process
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Pm, atomic number 61, promethium
a soft silvery metallic element of the rare earth group having no stable isotope; was discovered in radioactive form as a fission product of uranium
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Pa, atomic number 91, protactinium, protoactinium
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
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Ra, atomic number 88, radium
an intensely radioactive metallic element that occurs in minute amounts in uranium ores
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Rn, atomic number 86, radon
a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health
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Re, atomic number 75, rhenium
a rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
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Rh, atomic number 45, rhodium
a white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinum
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Rb, atomic number 37, rubidium
a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite
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Ru, atomic number 44, ruthenium
a rare polyvalent metallic element of the platinum group; it is found associated with platinum
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Sm, atomic number 62, samarium
a grey lustrous metallic element of the rare earth group; is used in special alloys; occurs in monazite and bastnasite
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Sc, atomic number 21, scandium
a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite
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Na, atomic number 11, sodium
a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
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Sr, atomic number 38, strontium
a soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite
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Ta, atomic number 73, tantalum
a hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
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Tc, atomic number 43, technetium
a crystalline metallic element not found in nature; occurs as one of the fission products of uranium
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Tb, atomic number 65, terbium
a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite
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Tl, atomic number 81, thallium
a soft grey malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores
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Th, atomic number 90, thorium
a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
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Tm, atomic number 69, thulium
a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime
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Sn, atomic number 50, tin
a silvery malleable metallic element that resists corrosion; used in many alloys and to coat other metals to prevent corrosion; obtained chiefly from cassiterite where it occurs as tin oxide
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Ti, atomic number 22, titanium
a light strong grey lustrous corrosion-resistant metallic element used in strong lightweight alloys (as for airplane parts); the main sources are rutile and ilmenite
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W, atomic number 74, tungsten, wolfram
a heavy grey-white metallic element; the pure form is used mainly in electrical applications; it is found in several ores including wolframite and scheelite
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U, atomic number 92, uranium
a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
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V, atomic number 23, vanadium
a soft silvery white toxic metallic element used in steel alloys; it occurs in several complex minerals including carnotite and vanadinite
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Xe, atomic number 54, xenon
a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
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Yb, atomic number 70, ytterbium
a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime
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Y, atomic number 39, yttrium
a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
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Zn, atomic number 30, zinc
a bluish-white lustrous metallic element; brittle at ordinary temperatures but malleable when heated; used in a wide variety of alloys and in galvanizing iron; it occurs naturally as zinc sulphide in zinc blende
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Zr, atomic number 40, zirconium
a lustrous grey strong metallic element resembling titanium; it is used in nuclear reactors as a neutron absorber; it occurs in baddeleyite but is obtained chiefly from zircon
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char
a charred substance
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charcoal, wood coal
a carbonaceous material obtained by heating wood or other organic matter in the absence of air
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alkali metal, alkaline metal
any of the monovalent metals of group I of the periodic table (lithium or sodium or potassium or rubidium or cesium or francium)
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alkaline earth, alkaline-earth metal
any of the bivalent metals of group II of the periodic table (calcium or strontium or barium or magnesium or beryllium)
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brimstone, native sulfur, native sulphur
an old name for sulfur
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carbon black, crock, lampblack, smut, soot
a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink
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activated carbon, activated charcoal
powdered or granular carbon used for purifying by adsorption; given orally (as a slurry) it is an antidote for some kinds of poisons
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black lead, graphite, plumbago
used as a lubricant and as a moderator in nuclear reactors
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adamant, diamond
very hard native crystalline carbon valued as a gem
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liquid nitrogen
nitrogen in a liquid state