atom bomb atomic bomb A-bomb fission bomb plutonium bomb | a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium or plutonium ) |
atomic clock | a timepiece that derives its time scale from the vibration of atoms or molecules |
atomic cocktail | an oral dose of radioactive substance used in treatment and diagnosis of cancer |
atomic pile atomic reactor pile chain reactor | a nuclear reactor that uses controlled nuclear fission to generate energy |
atomic warhead nuclear warhead thermonuclear warhead nuke | the warhead of a missile designed to deliver an atom bomb |
nuclear weapon atomic weapon | a weapon of mass destruction whose explosive power derives from a nuclear reaction |
atomic mass atomic weight relative atomic mass | (chemistry) the mass of an atom of a chemical element expressed in atomic mass units |
nuclear physics atomic physics nucleonics | the branch of physics that studies the internal structure of atomic nuclei |
atomism atomic theory atomist theory atomistic theory | (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles, the ancient Greek philosophers Democritus and Epicurus held atomic theories of the universe |
atomic theory | a theory of the structure of the atom |
nuclear explosion atomic explosion | the explosion of an atomic bomb |
Atomic Energy Commission AEC | a former executive agency (from to ) that was responsible for research into atomic energy and its peacetime uses in the United States |
International Atomic Energy Agency IAEA | the United Nations agency concerned with atomic energy |
atomic energy nuclear energy | the energy released by a nuclear reaction |
atomic power nuclear power | nuclear energy regarded as a source of electricity for the power grid (for civilian use) |
atomic spectrum | (physics) a spectrum of radiation caused by electron transitions within an atom, the series of spectrum lines is characteristic of the element |
atomic number | the order of an element in Mendeleyev's table of the elements, equal to the number of protons in the nucleus or electrons in the neutral state of an atom of an element |
atomic mass unit | unit of mass for expressing masses of atoms or molecules |
gram atom gram-atomic weight | the quantity of an element whose weight in grams is numerically equal to the atomic weight of the element |
actinium Ac atomic number | a radioactive element of the actinide series, found in uranium ores |
aluminum aluminium Al atomic number | a silvery ductile metallic element found primarily in bauxite |
americium Am atomic number | a radioactive transuranic metallic element, discovered by bombarding uranium with helium atoms |
antimony Sb atomic number | a metallic element having four allotropic forms, used in a wide variety of alloys, found in stibnite |
argon Ar atomic number | a colorless and odorless inert gas, one of the six inert gases, comprises approximately % of the earth's atmosphere |
arsenic As atomic number | 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 |
astatine At atomic number | a highly unstable radioactive element (the heaviest of the halogen series), a decay product of uranium and thorium |
barium Ba atomic number | a soft silvery metallic element of the alkali earth group, found in barite |
berkelium Bk atomic number | a radioactive transuranic element, discovered by bombarding americium with helium |
beryllium Be glucinium atomic number | a light strong brittle grey toxic bivalent metallic element |
bismuth Bi atomic number | a heavy brittle diamagnetic trivalent metallic element (resembles arsenic and antimony chemically), usually recovered as a by-product from ores of other metals |
bohrium Bh element atomic number | a transuranic element |
boron B atomic number | a trivalent metalloid element, occurs both in a hard black crystal and in the form of a yellow or brown powder |
bromine Br atomic number | a nonmetallic heavy volatile corrosive dark brown liquid element belonging to the halogens, found in sea water |
cadmium Cd atomic number | a soft bluish-white ductile malleable toxic bivalent metallic element, occurs in association with zinc ores |
calcium Ca atomic number | 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 |
californium Cf atomic number | a radioactive transuranic element, discovered by bombarding curium with alpha particles |
carbon C atomic number | an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond, occurs in all organic compounds |
cerium Ce atomic number | a ductile grey metallic element of the lanthanide series, used in lighter flints, the most abundant of the rare-earth group |
cesium caesium Cs atomic number | a soft silver-white ductile metallic element (liquid at normal temperatures), the most electropositive and alkaline metal |
chlorine Cl atomic number | 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) |
chromium Cr atomic number | a hard brittle multivalent metallic element, resistant to corrosion and tarnishing |
cobalt Co atomic number | a hard ferromagnetic silver-white bivalent or trivalent metallic element, a trace element in plant and animal nutrition |
copper Cu atomic number | a ductile malleable reddish-brown corrosionesistant 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 |
curium Cm atomic number | a radioactive transuranic metallic element, produced by bombarding plutonium with helium nuclei |
darmstadtium Ds element atomic number | a radioactive transuranic element |
dubnium Db hahnium element atomic number | a transuranic element |
dysprosium Dy atomic number | a trivalent metallic element of the rare earth group, forms compounds that are highly magnetic |
einsteinium Es E atomic number | a radioactive transuranic element produced by bombarding plutonium with neutrons |
erbium Er atomic number | a trivalent metallic element of the rare earth group, occurs with yttrium |
europium Eu atomic number | a bivalent and trivalent metallic element of the rare earth group |