1. Equal
2. Properties
3. Heat
4. Reverse
A chemical reaction occurs only when the collision between the reacting molecules takes place. However, not all the collisions are efficient in making the reaction. The products are produced only when the molecules colliding exhibits a certain kind of minimum energy known as threshold energy.
The threshold energy refers to the least amount of energy needed for the reactants to collide effectively, and to produce the activated complex. It is kinetic energy in supplementation with the energy of activation. Hence, threshold energy is more in comparison to the activation energy.