atomic number

noun
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. Abbreviation: at. no.; Symbol: Z
Also called proton number.


Origin:
1815–25

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2013.
Cite This Source Link To atomic number
Collins
World English Dictionary
atomic number
 
n
at. no., Z, Also called: proton number the number of protons in the nucleus of an atom of an element

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
00:10
Atomic number is always a great word to know.
So is gobo. Does it mean:
a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.
American Heritage
Medical Dictionary

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 American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
atomic number  
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 American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
American Heritage
Cultural Dictionary

atomic number definition


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.)

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Example sentences
The higher atomic number elements are created by supernovas.
All you need is the atomic number and a geometric structure.
Elements may be selected by their atomic number, or by their chemical symbol.
The process of creating higher atomic number elements from lower ones is fusion.
Copyright © 2013 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT