Question

photosynthesis is an example of
an exothermic reaction.
an endothermic reaction.
a reaction that gives off heat.
a reaction that emits energy.

Explanation:

To determine the correct option, we analyze the nature of photosynthesis:

• Exothermic reactions release heat/energy (e.g., combustion). Photosynthesis does not release heat; it absorbs light energy to convert \(CO_2\) and \(H_2O\) into glucose and \(O_2\). Thus, options about giving off heat or emitting energy (and exothermic) are incorrect.
• Endothermic reactions absorb energy from the surroundings. Photosynthesis absorbs light energy (from the sun) to drive the reaction, so it is endothermic.

Answer:

B. an endothermic reaction.