Chemical reactions occur when molecules or atoms collide so that the bonds between atoms break and new bonds form. Breaking the bonds of the reactants requires energy; whereas

Answer: Formation of bond releases energy.

Explanation:

In a chemical reaction, the chemical species collide with each other in order to break bonds between them and form new bonds.

During a chemical reaction, the bonds between the reactant molecules break and new bonds are formed to produce products.

To break the bonds between the reactant molecules, energy is required to overcome the attraction between the atoms.

To form new bonds, energy gets released when two atoms come close to each other.

Hence, formation of bond releases energy.