Found 2 items, similar to Atomic weight.
English → English (WordNet) Definition: atomic weight atomic weight n : (chemistry) the ratio of the atomic mass of an element to half the atomic mass of carbon-12 [syn: relative atomic mass ]
English → English (gcide) Definition: Atomic weight Weight \Weight\, n. [OE. weght, wight, AS. gewiht; akin to D. gewigt, G. gewicht, Icel. v[ae]tt, Sw. vigt, Dan. v[ae]gt. See Weigh, v. t.] [1913 Webster] 1. The quality of being heavy; that property of bodies by which they tend toward the center of the earth; the effect of gravitative force, especially when expressed in certain units or standards, as pounds, grams, etc. [1913 Webster] Note: Weight differs from gravity in being the effect of gravity, or the downward pressure of a body under the influence of gravity; hence, it constitutes a measure of the force of gravity, and being the resultant of all the forces exerted by gravity upon the different particles of the body, it is proportional to the quantity of matter in the body. [1913 Webster] 2. The quantity of heaviness; comparative tendency to the center of the earth; the quantity of matter as estimated by the balance, or expressed numerically with reference to some standard unit; as, a mass of stone having the weight of five hundred pounds. [1913 Webster] For sorrow, like a heavy-hanging bell, Once set on ringing, with his own weight goes. --Shak. [1913 Webster] 3. Hence, pressure; burden; as, the weight of care or business. “The weight of this said time.” --Shak. [1913 Webster] For the public all this weight he bears. --Milton. [1913 Webster] [He] who singly bore the world's sad weight. --Keble. [1913 Webster] 4. Importance; power; influence; efficacy; consequence; moment; impressiveness; as, a consideration of vast weight. [1913 Webster] In such a point of weight, so near mine honor. --Shak. [1913 Webster] 5. A scale, or graduated standard, of heaviness; a mode of estimating weight; as, avoirdupois weight; troy weight; apothecaries' weight. [1913 Webster] 6. A ponderous mass; something heavy; as, a clock weight; a paper weight. [1913 Webster] A man leapeth better with weights in his hands. --Bacon. [1913 Webster] 7. A definite mass of iron, lead, brass, or other metal, to be used for ascertaining the weight of other bodies; as, an ounce weight. [1913 Webster] 8. (Mech.) The resistance against which a machine acts, as opposed to the power which moves it. [Obs.] [1913 Webster] Atomic weight. (Chem.) See under Atomic, and cf. Element. Dead weight, Feather weight, Heavy weight, Light weight , etc. See under Dead, Feather, etc. Weight of observation (Astron. & Physics), a number expressing the most probable relative value of each observation in determining the result of a series of observations of the same kind. [1913 Webster] Syn: Ponderousness; gravity; heaviness; pressure; burden; load; importance; power; influence; efficacy; consequence; moment; impressiveness. [1913 Webster] Atomic \A*tom"ic\, Atomical \A*tom"ic*al\, a. [Cf. F. atomique.] 1. Of or pertaining to atoms. [1913 Webster] 2. Extremely minute; tiny. [1913 Webster] Atomic bomb, see atom bomb in the vocabulary. Atomic philosophy, or Doctrine of atoms, a system which, assuming that atoms are endued with gravity and motion, accounted thus for the origin and formation of all things. This philosophy was first broached by Leucippus, was developed by Democritus, and afterward improved by Epicurus, and hence is sometimes denominated the Epicurean philosophy. Atomic theory, or the Doctrine of definite proportions (Chem.), teaches that chemical combinations take place between the supposed ultimate particles or atoms of bodies, in some simple ratio, as of one to one, two to three, or some other, always expressible in whole numbers. Atomic weight (Chem.), the weight of the atom of an element as compared with the weight of the atom of hydrogen, taken as a standard. [1913 Webster]