Q: Chemical reactions either require or release what?


Read this paragraph and choose the correct option from the provided answers:

Chemical reactions either require energy or release energy. The amount of energy needed or released depends upon the structure of the molecules that are involved in the reaction. Some reactions need to be heated for long periods of time in order for change to take place. Other reactions release energy, allowing heat to be given off to the surroundings.

 Choices:

- light

- electricity

- enzymes

- energy


A:
energy