Activation Energy
Scientific Definition
Activation energy is the minimum amount of energy that reacting particles must possess for a chemical reaction to occur. It represents the energy barrier that must be overcome for the transformation of reactants into products.
This energy is required to break bonds in the reactant molecules, enabling the formation of new bonds during the reaction.
Illustrative Examples
- When striking a match, the heat generated by friction provides activation energy to start the combustion process.
- In biological systems, enzymes lower the activation energy to allow reactions to proceed at body temperature.
- Rusting of iron requires activation energy from environmental factors like heat and moisture.
Why Activation Energy Matters
- Controls Reaction Speed: Higher activation energy means a slower reaction unless additional energy is supplied.
- Determines Temperature Dependence: Many reactions require heating to supply sufficient activation energy.
- Explains Catalysis: Catalysts lower the activation energy, increasing reaction rates without being consumed.
Understanding activation energy is crucial in fields such as chemistry, biology, engineering, and environmental science.