Question

Which of the following helped in confirming that oxygen evolved in photosynthesis comes from water?

• A. $H_2{}^{18}O$
• B. ${}^{14}C{O}_2$
• C. ${}^{15}N{O}_3$
• D. ${}^3{H}_{2}O$.

Answer 1

The correct option is A $H_2{}^{18}O$

In the process of photosynthesis, water acts as a stable oxygen donor. To prove the theory radioisotopic technique was used.

Instead of the normal oxygen, the radioisotope was taken. It was seen that after the oxidation of water, the oxygen formed was ¹⁸O₂.

So, the correct option is '¹⁸O'