activation energy
Học thuậtThân thiện
Definition
Noun: The minimum amount of energy required to initiate a chemical reaction. It is the energy barrier that must be overcome for reactant molecules to transform into product molecules.
Usage
This term is used primarily in the fields of chemistry and physics to describe the threshold energy for a reaction. * The reaction did not proceed because the temperature was too low to provide the necessary activation energy. * A catalyst works by lowering the activation energy of a reaction, allowing it to happen faster.
Advanced Usage
- In Transition State Theory: The activation energy is the difference in energy between the reactants and the activated complex (transition state) of a reaction.
- In the Arrhenius Equation: The activation energy (Eₐ) is a key variable in the Arrhenius equation (k = A e^(-Eₐ/RT)), which describes the temperature dependence of reaction rates.
Variants and Related Words
- Energy of Activation: A synonymous phrase.
- Activation Barrier: A closely related term emphasizing the "barrier" that must be overcome.
Synonyms
Energy of activation; energy barrier (in a chemical context).
Related Phrases
- To overcome the activation energy: To supply sufficient energy for a reaction to start.
- The spark provided enough heat to overcome the activation energy for combustion.
- To lower/reduce the activation energy: To decrease the energy required, often through the use of a catalyst.
- Enzymes function by lowering the activation energy of biochemical reactions.
Noun
- the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur
- catalysts are said to reduce the energy of activation during the transition phase of a reaction