Answer:
At Transition state stage of a reaction do atoms have the highest energy.
Explanation:
In a chemical reactions reactants reacts to produce products. Reactants have their specific energies and products have their own. If energy of reactants is greater than that of products then it is exothermic reaction, or if it is less than that of products then it is endothermic reaction.
When reactants approaches each other in order to react their old bonds start breaking and new bonds start forming. This stage of partial bonds is called as Transition state. Transition state has very high energy as compared to energies of reactants and products. Therefore, due to its high energy it is very unstable and exists for a very short period of time and converts into products.