Go to MSN Homeencarta®
Dictionary
Find
in
Dictionary
Thesaurus
Translations
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Click to move up the list of words
active listening
active market
active-matrix display
active packaging
active participation
active portfolio strategy
active server page
active service
active site
active transport
active vocabulary
activism
activist fiscal policy
activity
activity rate
actomyosin
actor
Click to move down the list of words
Also available:

World English Dictionary
Dictionnaire Français

activation energy
ac·ti·va·tion en·er·gy


noun 
Definition:
 
energy to convert molecules: the energy needed to make molecules of a substance take part in a chemical reaction
Encarta® World English Dictionary [North American Edition] © & (P)2009 Microsoft Corporation. All rights reserved. Developed for Microsoft by Bloomsbury Publishing Plc.
Advertisement
© 2009 Microsoft