Q: What do all chemical changes require to occur?
Options:
- (A) during the day
- (B) heating liquids
- (C) Activation energy
- (D) wavelengths and photons
- (E) Burning fuel and air
- (F) kinetic energy
- (G) electromagnetic energy
- (H) direct energy
Let's think step by step below.
All chemical reactions require activation energy to get started. Chemical changes are a result of chemical reactions. All chemical changes require activation energy to occur.
Thus, the answer is (C).