Chemical reactions

5. Reactions in which heat energy is absorbed
7. Reaction where one or a group of atoms is displaced by a more reactive atom or group of atoms
9. Type of decomposition reaction where the compound decomposes on exposure to light
11. Eating up of metals as a result of exposure to air, moisture or other gasses
14. Reactions in which heat is released along with the products
15. Substance that helps speed up the chemical reaction
16. Process which involves loss of oxygen or gain of hydrogen

1. Chemical equation using symbols and formulae for reactants and products
2. Substance that gives hydrogen or gains oxygen
3. Substance that gives oxygen or gains hydrogen
4. Reaction where a single substance decomposes to give 2 or more substances
6. Reaction in which insoluble salts are formed
8. Reaction where two or more substances combine to form a single substance
10. Equalize number of atoms on either side of the equation using the smallest coefficients
12. Process which involves gain of oxygen or loss of hydrogen
13. Oxidation of oils or fats in food resulting in bad smell or taste