activation energy

noun

, Chemistry.

1. the least amount of energy required to activate atoms or molecules to a state in which they can undergo a chemical reaction.

activation energy

/ ăk′tə-vā′shən /

1. The least amount of energy needed for a chemical reaction to take place. Some elements and compounds react together naturally just by being close to each other, and their activation energy is zero. Others will react together only after a certain amount of energy is added to them. Striking a match on the side of a matchbox, for example, provides the activation energy (in the form of heat produced by friction) necessary for the chemicals in the match to ignite. Activation energy is usually expressed in terms of joules per mole of reactants.

Word History and Origins

Origin of activation energy¹

First recorded in 1920–25

Example Sentences

The calculation of OTOCs showed that chemical reactions with a low activation energy at low temperatures where tunneling dominates can scramble information at nearly the quantum limit, like a black hole.

From Science Daily

The activation energy of ionic conduction of this material is extremely low, and the ionic conductivity of this material at low temperature is one of the highest among known solid electrolytes, including sulfide-based materials.

From Science Daily

Rather, being bored means wanting to connect and interact with someone or something, but finding no outlet for that activation energy.

From Salon

However, there remains a high activation energy requirement, as simply getting umumium into a situation where it will even approach another element is nigh on impossible.

From Nature

At home, our television is not easily accessible, so that there is “activation energy” before you can easily go watch TV.

From New York Times