The following is the correct list of matching:
1. A fire started without any help - Spontaneous combustion.
2. Most dangerous radiation - gamma rays.
3. Rusting - slow oxidation.
4. Product of acid and base - Salt.
5. Substances united in a reaction - reactants.
6. A reaction which takes in energy - Endothermic
7. Contains mineral salts - Hard water.
8. Nuclei and free electrons - Plasma phase.
9. Fueled by fusion - Sun.
