one of two or more atoms having an equal number of neutrons but different atomic numbers.
Origin of isotone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
one of two or more atoms of different atomic number that contain the same number of neutrons
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
One of two or more atoms whose nuclei have the same number of neutrons but different numbers of protons.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.