Smallest particle still characterizing a
chemical element. It consists of a
nucleus of a positive charge
(
is the
proton number and
the
elementary charge) carrying almost all its mass (more than 99.9%) and
electrons determining its size.
Source:
Physical Chemistry Division, unpublished
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
