| A | B |
|---|
| reactants | A substance that enters into a chemical reaction |
| products | A substance formed as a result of a chemical reation |
| Conservation of mass | The principle stating that matter is not created or destroyed during a chemical reaction |
| coefficient | A number in front of a chemical formula in an equation that indicates how many molecules or atoms there are |
| synthesis | A chemical reaction in which two or more simple substance combine to form a new, more complex substance |
| exothermic reaction | A reaction that releases energy in the form of heat |
| replacement | A reaction in which one element replaces another in a compound; or when two elements in different compound trade places |
| endothermic reaction | A reaction that absorbs energy in the form of heat |
| catalyst | A meterial that increases the rate of a chemical reaction by lowering the activation energy |
| element | A substance that cannot be broken down into any other substances by chemical or physical means |
| chemical reaction | The process in which substances undergo chemical changes that result in the formation of new substances |
| compound | A substance made of two or more elements chemically combined in a specific ration or proportion |
| mixture | Two or more substances that are mixed together but not chemically combined |
| chemical bond | A force that holds atoms together |
| solution | A well-mixed mixture |
| chemical equation | A short, easy way to show a chemical reaction, using symbols instead of words |
| physical change | A change that alters the form or appearance of a material but does not make the material into another substance |
| chemical formula | A combination of symbols that represent the elements in a compound |
| chemical change | A change in matter that produces a new substance |
| subscript | A number in a chemical formula that tells the number of atoms in a molecule or the ratio of elements |
