Question: How do catalysts affect a chemical reaction?

Answer: lower activation energy

Question: What happens during rusting of an iron nail?

Answer: Iron and oxygen combine to form iron oxide.

Question: What does the forward arrow in a chemical equation mean?

Answer: The reaction yields something.

Question: Which kind of reaction is photosynthesis?

Answer: endothermic

Question: Photosynthesis requires which kind of energy?

Answer: light energy