atom'ic

Pertaining to atoms, a. heat. The product of the a. weight and the specific heat of an element. a. theory. See under theory. a. volume. The volume which a gram atom of an element takes up in the gaseous form. a. weight. The relative weight of an atom of an element with oxygen, 16, as a unit. ATRIUM atom i'city. Syn.: combining capacity (or power), quantivalence, valence, valency. The combining power of an element as compared with that of hydrogen; a number representing the greatest number of atoms of hydrogen which it will replace in a compound, or with which it is capable of combining, or twice the number of oxygen atoms with which one of its atoms can combine. The degrees of a. are expre ed by the terms univalence, or the a. of a monad element, which replaces one atom of hydrogen; bivalence, or the a. of a diad element, replacing two atoms of hydrogen; trivalence, or the a. of a triad element; quadrivalence, or the a. of a tetrad element; quin qui valence, or the a. of a pentad element; sex valence, or the a. of a hexad element; etc..