The statement "The amount of $CO_2$ absorbed and $O_2$ released during photosynthesis are in equal volumes" was proved by:

In photosynthesis,if we radiolabel the oxygen atom in $CO_2$,which product will become radiolabeled?

Evaluate the following statements regarding $T$. $W$. Engelmann's experiment:
$1.$ $T$. $W$. Engelmann stated that chlorophyll present in algae absorbs light of green and orange colors,splits water molecules by photolysis,and releases $O_2$.
$2.$ Aerobic bacteria accumulate near the algae to utilize the released $O_2$.

In bacterial photosynthesis,the hydrogen donor is:

What was the difference between Priestley and Ingenhousz's experiment?

Through the use of oxygen $-18$ (heavy oxygen),scientists have found that the oxygen released during photosynthesis comes from molecules of