follow Dictionary.com

What does Boxing Day have to do with boxing?

at. no.

1.
atomic number.

atomic number

noun
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. Symbol: Z.
Abbreviation: at. no.;
Also called proton number.
Origin
1815-1825
1815-25
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for at. no

at. no.

abbreviation
1.
atomic number

atomic number

noun
1.
the number of protons in the nucleus of an atom of an element at. no., Z Also called proton number
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
at. no in Medicine

at. no. or at no
abbr.
atomic 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 American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
at. no in Science
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
at. no in Culture

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
Related Abbreviations for at. no

at. no.

atomic number
The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for at. no.

Few English speakers likely know this word

Word Value for at

2
2
Scrabble Words With Friends

Quotes with at. no

Nearby words for at. no