| A | B |
|---|
| subscript | the number that describes how many of each atom |
| coefficient | the number that describes how many molecules |
| chemical reaction | atoms combine or recombine to form new molecules (substances) |
| endothermic reaction | heat energy is absorbed - feels cold |
| exothermic reaction | heat energy is released - feels hot |
| Law of Conservation of Matter | matter cannot be created or destroyed, only rearranged |
| reactant | the starting chemicals in a reaction |
| product | the ending chemicals in a reaction |
