Answer:
Oxygen
Step-by-step explanation:
During the light dependent stage of Photosynthesis, water that was absorbed and transported to leaves are split apart by heat energy which was converted from the light energy from the sun that got trapped by the chlorophyll in the chloroplast.
when the water(H2O) is split apart, oxygen is given off as a by-product while the Hydrogen is later used in the light independent where it combines with CO2 from to atmosphere to make glucose.
light dependent equation:
2H2O(l) + (light energy) --> 2H2(g) + O2(g)
water --> Hydrogen + oxygen