This word is used in different senses:
-
Input of external energy into a chemical system is said to bring about activation of the system.
-
An added substance that increases the rate of a catalysed reaction is known as an activator, and the effect is called activation. The degree of activation
is defined by:
where 
is the rate of the catalysed reaction in the absence of the activator
and 
is the rate of the catalysed reaction in the presence of the activator
-
When some of the energy required for a reaction to occur is provided by a previous exothermic chemical reaction there is said to be chemical activation.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996))
on page 151
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.
doi:10.1351/goldbook.
