Have to remember that chemistry stuffs.

Exothermic reactions are reactions in which heat energy is released.
Endothermic reactions are reactions in which heat energy is absorbed.

Exothermic reactions are negative, while endothermic reactions are positive.

The particles would gain heat energy, move faster,
allowing an increase in chances of successful collisions.

Activation energy is the minimum amount of energy the reactants must require
in order to have success collisions to produce products.

Bond energy is heat energy absorbed to break one mole of covalent bond
OR
Bond energy is heat energy released to make one mole of covalent bond.

Catalyst is required to increase the rate of reactions by
breaking the chemical bonds between reactant molecules.

The lower the activation energy, the higher the rate of reactions.

Sorry for this post. I need to remember all this stuffs. ^^