chemical element

Definitions of chemical element
  1. noun
    any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
    synonyms: element
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    allotrope
    a structurally different form of an element
    transuranic element
    any element having an atomic number greater than 92 (which is the atomic number of uranium); all are radioactive
    argonon, inert gas, noble gas
    any of the chemically inert gaseous elements of the helium group in the periodic table
    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.
    nonmetal
    a chemical element lacking typical metallic properties
    transactinide
    any of the artificially produced elements with atomic numbers greater than 103
    Ac, actinium, atomic number 89
    a radioactive element of the actinide series; found in uranium ores
    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
    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
    At, astatine, atomic number 85
    a highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium
    Bh, atomic number 107, bohrium, element 107
    a transuranic element
    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
    Br, atomic number 35, bromine
    a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens; found in sea water
    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
    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)
    Ds, atomic number 110, darmstadtium, element 110
    a radioactive transuranic element
    Db, atomic number 105, dubnium, element 105, hahnium
    a transuranic element
    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
    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
    Hs, atomic number 108, element 108, hassium
    a radioactive transuranic element
    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)
    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
    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)
    Kr, atomic number 36, krypton
    a colorless element that is one of the six inert gasses; occurs in trace amounts in air
    Lr, atomic number 103, lawrencium
    a radioactive transuranic element synthesized from californium
    Mt, atomic number 109, element 109, meitnerium
    a radioactive transuranic element
    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)
    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
    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
    No, atomic number 102, nobelium
    a radioactive transuranic element synthesized by bombarding curium with carbon ions; 7 isotopes are known
    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
    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
    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
    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
    Rg, atomic number 111, element 111, roentgenium
    a radioactive transuranic element
    Rf, Unq, atomic number 104, element 104, rutherfordium, unnilquadium
    a radioactive transuranic element which has been synthesized
    Sg, atomic number 106, element 106, seaborgium
    a transuranic element
    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)
    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
    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)
    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
    Uub, atomic number 112, element 112, ununbium
    a radioactive transuranic element
    Uuh, atomic number 116, element 116, ununhexium
    a radioactive transuranic element
    Uup, atomic number 115, element 115, ununpentium
    a radioactive transuranic element
    Uuq, atomic number 114, element 114, ununquadium
    a radioactive transuranic element
    Uut, atomic number 113, element 113, ununtrium
    a radioactive transuranic element
    Xe, atomic number 54, xenon
    a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
    trace element
    an element that occurs at very small quantities in the body but is nonetheless important for many biological processes
    metalloid
    a nonmetallic element that has some of the properties of metal
    tritium
    a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms
    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)
    base metal
    a metal that is common and not considered precious
    fullerene
    a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms
    noble metal
    any metal that is resistant to corrosion or oxidation
    Al, aluminium, aluminum, atomic number 13
    a silvery ductile metallic element found primarily in bauxite
    Am, americium, atomic number 95
    a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms
    Sb, antimony, atomic number 51
    a metallic element having four allotropic forms; used in a wide variety of alloys; found in stibnite
    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
    Ba, atomic number 56, barium
    a soft silvery metallic element of the alkali earth group; found in barite
    Bk, atomic number 97, berkelium
    a radioactive transuranic element; discovered by bombarding americium with helium
    Be, atomic number 4, beryllium, glucinium
    a light strong brittle grey toxic bivalent metallic element
    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
    Cd, atomic number 48, cadmium
    a soft bluish-white ductile malleable toxic bivalent metallic element; occurs in association with zinc ores
    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
    Cf, atomic number 98, californium
    a radioactive transuranic element; discovered by bombarding curium with alpha particles
    carbon 14, radiocarbon
    a radioactive isotope of carbon
    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
    Cs, atomic number 55, caesium, cesium
    a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal
    radiochlorine
    a radioactive isotope of chlorine
    Cr, atomic number 24, chromium
    a hard brittle multivalent metallic element; resistant to corrosion and tarnishing
    Co, atomic number 27, cobalt
    a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
    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
    Cm, atomic number 96, curium
    a radioactive transuranic metallic element; produced by bombarding plutonium with helium nuclei
    Dy, atomic number 66, dysprosium
    a trivalent metallic element of the rare earth group; forms compounds that are highly magnetic
    E, Es, atomic number 99, einsteinium
    a radioactive transuranic element produced by bombarding plutonium with neutrons
    Er, atomic number 68, erbium
    a trivalent metallic element of the rare earth group; occurs with yttrium
    Eu, atomic number 63, europium
    a bivalent and trivalent metallic element of the rare earth group
    Fm, atomic number 100, fermium
    a radioactive transuranic metallic element produced by bombarding plutonium with neutrons
    Fr, atomic number 87, francium
    a radioactive element of the alkali-metal group discovered as a disintegration product of actinium
    Gd, atomic number 64, gadolinium
    a ductile silvery-white ductile ferromagnetic trivalent metallic element of the rare earth group
    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
    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
    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)
    Ho, atomic number 67, holmium
    a trivalent metallic element of the rare earth group; occurs together with yttrium; forms highly magnetic compounds
    In, atomic number 49, indium
    a rare soft silvery metallic element; occurs in small quantities in sphalerite
    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
    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
    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
    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
    Kr, atomic number 36, krypton
    a colorless element that is one of the six inert gasses; occurs in trace amounts in air
    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
    Pb, atomic number 82, lead
    a soft heavy toxic malleable metallic element; bluish white when freshly cut but tarnishes readily to dull grey
    Li, atomic number 3, lithium
    a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals
    Lu, atomic number 71, lutecium, lutetium
    a trivalent metallic element of the rare earth group; usually occurs in association with yttrium
    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)
    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
    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
    Mo, atomic number 42, molybdenum
    a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel
    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
    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
    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
    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
    Nb, atomic number 41, niobium
    a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
    azote
    an obsolete name for nitrogen
    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
    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
    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
    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
    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
    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
    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
    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
    Pa, atomic number 91, protactinium, protoactinium
    a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
    Ra, atomic number 88, radium
    an intensely radioactive metallic element that occurs in minute amounts in uranium ores
    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
    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
    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
    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
    Ru, atomic number 44, ruthenium
    a rare polyvalent metallic element of the platinum group; it is found associated with platinum
    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
    Sc, atomic number 21, scandium
    a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveitite
    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)
    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
    Ta, atomic number 73, tantalum
    a hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
    Tc, atomic number 43, technetium
    a crystalline metallic element not found in nature; occurs as one of the fission products of uranium
    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
    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
    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
    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
    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
    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
    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
    U, atomic number 92, uranium
    a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
    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
    Xe, atomic number 54, xenon
    a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
    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
    Y, atomic number 39, yttrium
    a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys
    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
    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
    char
    a charred substance
    charcoal, wood coal
    a carbonaceous material obtained by heating wood or other organic matter in the absence of air
    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)
    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)
    brimstone, native sulfur, native sulphur
    an old name for sulfur
    carbon black, crock, lampblack, smut, soot
    a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink
    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
    black lead, graphite, plumbago
    used as a lubricant and as a moderator in nuclear reactors
    adamant, diamond
    very hard native crystalline carbon valued as a gem
    liquid nitrogen
    nitrogen in a liquid state
    type of:
    substance
    the real physical matter of which a person or thing consists
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