The state in which the element is stable
at a chosen standard-state pressure and for a given temperature.
PAC, 1982, 54, 1239
(Notation for states and processes, significance of the word standard in chemical
thermodynamics, and remarks on commonly tabulated forms of thermodynamic functions)
on page 1249
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