This is understood to be the geometrical or projected area, and to ignore surface
roughness.
Source:
PAC, 1985, 57, 1491
(Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations
1985))
on page 1493
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.