noun

• The minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.

  ‘The energy that is required to activate molecules for a chemical reaction is the activation energy of the reaction.’

  More example sentences

  • ‘In addition, to cause a reaction the colliding reactant molecules must surpass a minimum energy termed the activation energy and, in many cases, the reactant molecules must have a certain spatial orientation with respect to each other.’
  • ‘Chemical reactions require a minimum or threshold energy, called the activation energy.’
  • ‘To get the reaction to proceed, either the activation energy must be supplied in the form of heat, or the activation energy must be lowered, using a catalyst.’
  • ‘Since, as transition state theory posits, a chemical reaction requires a specific level of energy, known as the activation energy, every initiated reaction is not automatically completed.’