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. Symbol: Z.
Abbreviation: at. no.;
The number found in this way is one less than the atomic number.
A Brief Account of Radio-activity Francis Preston Venable
Their principal food is the radio-active element, atomic number 109, as yet undiscovered on the planets.
The Revolt of the Star Men Raymond Gallun
the number of protons in the nucleus of an atom of an element at. no., Z Also called proton number
atomic number n.
Abbr. at. no., at no
The number of protons in an atomic nucleus; it indicates the position of an element in the periodic table.
The number of protons in the nucleus of an atom. In electrically neutral atoms, this number is also equal to the number of electrons orbiting about the atom’s nucleus. The atomic number of an element determines its position in the Periodic Table, and is usually denoted by the letter Z and written as a subscript before an element’s symbol, as in 92U.
The number of protons or electrons normally found in an atom of a given chemical element. The higher the atomic number, the heavier the atom is. In a neutral atom, the number of protons and electrons is the same. (See atomic weight and periodic table of the elements.)
- Atomic orbital
See under (def 2). of or relating to an . Physics, Chemistry. a wave function describing the state of a single electron in an atom (atomic orbital) or in a molecule (molecular orbital) the electron in that state. adjective of or denoting an orbit (of a motorway or major road circuit) circling a large city […]
- Atomic pile
(def 4). Historical Examples Trailing the wheel ten miles off, was the atomic pile, directly attached to its anchor tube. Where I Wasn’t Going Walt Richmond The atomic pile levers were still at their proper calibration. Atom Drive Charles Louis Fontenay This ship is powered by a nuclear reactor—in other words, an atomic pile. Rip […]
- Atomic power
. Historical Examples As we now realize, atomic power cannot be utilized on a minute scale. This Crowded Earth Robert Bloch Ilg located an atomic power source, and fed the data to Pid. Keep Your Shape Robert Sheckley He wrote: Feudal anachronisms and atomic power, side by side. Teething Ring James Causey They had landed […]
- Atomic radius
noun the radius of an atom; the distance from the atomic nucleus to the outermost stable electron orbital in a atom at equilibrium; also, one-half the distance between nuclei of atoms of the same element, when the atoms are bound by a single covalent bond or are in a metallic crystal