Given a scientific question, generate a correct answer to it.

[EX Q]: What form of radiation is the energy emitted by the sun?
[EX A]: electromagnetic

[EX Q]: A mixture of a metal with one or more other elements is called?
[EX A]: an alloy

[EX Q]: Plants and algae maintain the atmosphere. during photosynthesis, they add oxygen and remove what?
[EX A]:
carbon dioxide