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action stations
action to quiet title
actionable
actioner
activate
activated alumina
activated carbon
activated sludge
activation energy
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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.
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