Answer:
Energy is absorbed in the given reaction because the reaction involves the breaking of bond which always involves the input of energy, i.e. bond-breaking is an exothermic reaction reaction.
Explanation:
Atoms of elements existing alone possess internal energies. When these atoms come together in bonding relationships as molecules or compounds, they lose or release their internal energy as heat in order to attain more stable state. Therefore, the bonded atoms in the molecules or compounds now possess lower energies than they possess as individual atoms.
In order for the bonds binding the atoms in the molecules or compound to be broken, an equal amount of energy to that released during bond formation is required. This energy is known as bond energy.
In the balanced equation of chemical reaction given below:
O₂(g) + energy ----> O(g) + O(g)
An oxygen molecule is broken down into two oxygen atoms. The process involves a breaking of the covalent bond holding the two atoms of oxygen together in the molecule of oxygen in order to release them as free atoms. Therefore, energy must be supplied or absorbed to break these bonds.
