How It Was Proved That Oxygen Evolved In Photosynthesis Is Derived From Water?

How It Was Proved That Oxygen Evolved In Photosynthesis Is Derived From Water? Photolysis of water is a part of the light-dependent reaction of the photosynthesis process. experimentally proved by Ruben and Kamen. 6. By the use of radioactive isotopes they found that oxygen comes from water. Who proved that oxygen? When Joseph Priestley discovered