Chlorophyll passes this energy to water molecules which further splits to form Hydrogen and Hydroxyl ions in the presence of light.
The energy content of products is less than the heat content of reactants.
Plants absorb Carbon dioxide from air and water from the soil, absorb the sun’s heat energy to initiate the process of photosynthesis and to produce carbohydrates.
Hence we can say that photosynthesis is an endothermic reaction.