What do all chemical changes require to occur?\nOptions:\n- (A) during the day\n- (B) heating liquids\n- (C) Activation energy\n- (D) wavelengths and photons\n- (E) Burning fuel and air\n- (F) kinetic energy\n- (G) electromagnetic energy\n- (H) direct energy
Let's think step by step below.
(C)
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.

.

Therefore, the answer is (C)