atomic number: Meaning and Definition of

atom'ic num'ber

Pronunciation: [key]
  1. the number of positive charges or protons in the nucleus of an atom of a given element, and therefore also the number of electrons normally surrounding the nucleus. Abbr.: at. no.; Symbol: Z Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.