| A | B |
|---|
| exothermic reaction | A reaction that releases energy in the form of heat |
| endothermic reaction | A reaction that absorbs energy in the form of hear |
| activation energy | The minimum amount of energythat has to be added to get a chemical reaction started |
| concentration | The amount of one material in a certain volume of another material |
| catalyst | A material that increases the rate of a chemical reaction by lowering the activation energy |
| enzyme | A biological catalyst that lowers the activation energy of reactions in cells |
| inhibitor | A material that decreases the rate of a reaction |
| combustion | A rapid reaction between oxygen and fuel that results in fire |
| fuel | A material that releases energy when it burns |
| chemistry | The studies of the properties of matter and how it changes |
| element | A substance that can not be broken down into any other substances by chemical or physical means |
| compound | Two or more substances that heve been chemically combined |
| mixture | Two or more substances that are mixed but not chemically combined |
| solution | A well mixed mixture |
| physical change | a change that alters the form of a substance but doesn't change it into a new substance |
| chemical change | A change in matter that produces a new substance |
| chemical reaction | The process in which substances undergo chemical change |
| precipitate | A solid that forms during a chemical reaction |
| atom | The smallest partical of an element |
| molecule | The combination of two or more atoms |
| chemical bond | The force that holds atoms together |
| Chemical equation | A short, easy way to show a chemical reaction using symbols rather than words |
| symbol | A one or two letter set of characters that is used to identify elements |
| chemical formula | A combination of symbols that represent the elements in a compound |
| subscript | A number in a chemical formula that tells the number of atoms in a molecule or the ratio of elements in a compound |
| reactant | A substance that enters into a chemical reaction |
| product | A substance formed as a result of a chemical reaction |
| conservation of mass | The principlestating 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 of each reactant and product are involved in a reaction |
| synthesis | A chemical reaction in which two or more simple substances combine to form a new, more complex substance |
| decomposition | A chemical reaction that breaks down compounds into simpler products |
| replacement reaction | A reaction in which one element replaces another in a compound; or when two elements in different compounds trade places |
