When some of the energy required for a reaction is provided by a preceding exothermic
chemical reaction there is said to be chemical activation. For example, in the scheme:
some or all of the energy required for X to decompose is provided by the first reaction.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
Recommendations 1996))
on page 158
