click below
click below
Normal Size Small Size show me how
Chemical reactions
| Term | Definition |
|---|---|
| chemical reaction | A process in which atoms of one or more substances rearrange to form one or more new substances. |
| chemical equation | A description of a reaction using element symbols and chemical formulas. |
| reactants | The starting substances produced by the chemical reaction. |
| products | The substances produced by the chemical reaction. |
| law of conservation of mass | States that the total mass of the reactants before a chemical reaction is the same as the total mass of the products after the chemical reaction. |
| coefficient | A number placed in front of an element symbol or chemical formula in an equation. |
| decomposition | One compound breaks down and forms two or more substances. |
| endothermic reaction | Chemical reactions that absorb thermal energy. (cold) |
| exothermic reaction | Chemical reaction that releases thermal energy. |
| What happens during a chemical change? | A NEW substance is produced. |
| what happens during a physical change? | The original substance still exists but physically is changed. |
| Precipitate | a solid formed from a liquid during a chemical reaction |