| A | B |
| chemical reaction | process in which substances change into new substances |
| reactant | substance that enters into a chemical reaction |
| product | substance produced by a chemical reaction |
| chemical equation | symbols, formulas and numbers representing a reaction |
| synthesis reaction | two or more substances combine to form new substance |
| decomposition reaction | complex substance breaks down into simpler substances |
| single-replacement reaction | uncombined element replaces an element in a compound |
| double-replacement reaction | different atoms in two compounds replace one another |
| exothermic reaction | energy is released |
| endothermic reaction | energy is absorbed |