Found 2 items, similar to Atomic weight.
English → English
Definition: 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
Definition: Atomic weight
, n. [OE. weght, wight, AS. gewiht; akin to D.
gewigt, G. gewicht, Icel. v[ae]tt, Sw. vigt, Dan. v[ae]gt.
, v. t.]
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.
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.
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.
For sorrow, like a heavy-hanging bell,
Once set on ringing, with his own weight goes.
3. Hence, pressure; burden; as, the weight of care or
business. “The weight of this said time.”
For the public all this weight he bears. --Milton.
[He] who singly bore the world's sad weight.
4. Importance; power; influence; efficacy; consequence;
moment; impressiveness; as, a consideration of vast
In such a point of weight, so near mine honor.
5. A scale, or graduated standard, of heaviness; a mode of
estimating weight; as, avoirdupois weight; troy weight;
6. A ponderous mass; something heavy; as, a clock weight; a
A man leapeth better with weights in his hands.
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.
8. (Mech.) The resistance against which a machine acts, as
opposed to the power which moves it. [Obs.]
. (Chem.) See under Atomic
, and cf.
, Feather weight
, Heavy weight
, Light weight
, etc. See under Dead
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.
Syn: Ponderousness; gravity; heaviness; pressure; burden;
load; importance; power; influence; efficacy;
consequence; moment; impressiveness.
, Atomical \A*tom"ic*al\
, a. [Cf. F. atomique.]
1. Of or pertaining to atoms.
2. Extremely minute; tiny.
, see atom bomb
in the vocabulary.
, 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
, 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.
(Chem.), the weight of the atom of an element
as compared with the weight of the atom of hydrogen, taken
as a standard.