atomic
121atomic number — atomic num·ber nəm bər n an experimentally determined number characteristic of a chemical element that represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside the nucleus and that determines… …
122atomic theory — n 1) a theory of the nature of matter: all material substances are composed of minute particles or atoms of a comparatively small number of kinds and all the atoms of the same kind are uniform in size, weight, and other properties called also… …
123atomic bomb — atomic bombs N COUNT (The form atom bomb is also used, mainly in British English.) An atomic bomb or an atom bomb is a bomb that causes an explosion by a sudden release of energy that results from splitting atoms …
124atomic mass unit — ► NOUN ▪ a unit of mass used to express atomic and molecular weights, equal to one twelfth of the mass of an atom of carbon 12 …
125atomic disintegration — n. a process resulting in the change of a radioactive nucleus, either by emission of an alpha, beta, or gamma ray or by fission, and producing a change in the original mass, atomic number, or energy …
126atomic mass unit — n. a unit of mass, exactly one twelfth the mass of a neutral atom of the most abundant isotope of carbon, C12: one atomic mass unit equals 1.6605 x 10 24 gram and is equivalent to 931.48 MeV in energy: symbol amu or u …
127atomic number — n. Chem. a number representing the relative position of an element in the periodic table, in which the elements are arranged in the order of their nuclear charges; a number representing the positive charge or the number of protons in the nucleus… …
128atomic volume — n. Chem. the quotient obtained by dividing the atomic weight of an element by its density …
