Fact 1: Afirecracker converts chemical energy into sound.

Fact 2: Chemical energy Energy released as a result of chemical reactions.

Given the two facts above, answer the question "What is happening inside a firecracker as it starts to go off?" with the following options: 
- separation
 - explosion
 - adding heat
 - chemical reaction
 - It remains dormant
 - wavelengths and photons
 - uncontrolled
 - fusion


 

    chemical reaction     