Concept:Photosynthesis converts light energy into chemical energy, and water is split into hydrogen and oxygen during the light reactions.Explanation:During photosynthesis, light energy is absorbed by chlorophyll.This energy drives the splitting of water molecules (H2O) into hydrogen ions (H+), electrons, and oxygen (O2).The oxygen is released as a byproduct.The hydrogen ions and electrons are then used to reduce carbon dioxide (CO2) to form carbohydrates.The overall chemical equation is:6CO2+6H2OSunlightChlorophyllC6H12O6+6O2Thus, water is oxidized (splits into hydrogen and oxygen), and carbon dioxide is reduced.Option A is incorrect because chemical energy is not converted to light energy; it is the reverse.Option B is incorrect because carbon dioxide is reduced, not oxidized.Option D is incorrect because light energy is not directly used to split water; it excites electrons, which then drive the splitting via an enzyme complex.Therefore, the correct statement is that water molecule splits into hydrogen and oxygen.
