Question

what molecule is split during the light - dependent reactions to release oxygen?
a. nadph
b. water (h2o)
c. glucose
d. carbon dioxide

Explanation:

In the light - dependent reactions of photosynthesis, water ($H_2O$) is split. This process, called photolysis of water, releases oxygen as a by - product. NADPH is a product of the light - dependent reactions, not a molecule that is split to release oxygen. Glucose is produced in the light - independent reactions (Calvin cycle). Carbon dioxide is used in the Calvin cycle and not split to release oxygen in the light - dependent reactions.

Answer:

B. Water (H2O)