For a chemical reaction to occur, the bonds within the reactants must be broken and new bonds must be formed between the atoms to make the products.The energy required to break the bonds is called the Activation energy Ea. It is the minimum energy required for the reaction to take place.Reactions with low activation energies take place rapidly because the energy needed to break the bonds is readily available from the surroundings.Reactions with very high activation energies will take place very slowly or not at all because the activation energy acts as an energy barrier to the reaction.The Maxwell-Boltzmann distribution shows the spread of energies of the molecules in a gas at a given temperature. Only the molecules with energy equal to or greater than Ea, shown by the area under the curve to the right of Ea, have enough energy to react.
The Maxwell-Boltzmann Distribution