What is activation energy

Activation energy is a term in chemistry and biology that refers to the minimum amount of energy that reactants must possess in order to undergo a specific reaction. It is denoted by the symbol Ea and is usually expressed in units of joules (J) or kilojoules per mole (kJ/mol).

Here are the steps to understand it:

1. Consider a chemical reaction where a set of reactants transform into products. This process often requires an initial input of energy to break certain bonds in the reactants and start the reaction. This is the activation energy.

2. The concept of activation energy was introduced by the Swedish scientist Svante Arrhenius in 1889. It is a crucial idea in the study of reaction rates.

3. Activation energy can be thought of as the energy barrier that must be overcome for the reactants to be converted into products. The higher the activation energy, the slower the chemical reaction.

4. The activation energy of a reaction can be lowered by the presence of a catalyst. A catalyst is a substance that increases the rate of a chemical reaction by lowering its activation energy.

5. The activation energy is determined experimentally by measuring the reaction rates at different temperatures and using the Arrhenius equation.

6. In biological systems, enzymes play the role of catalysts. They lower the activation energy required for biochemical reactions to occur, allowing these reactions to take place at the temperatures present in living organisms.