| A | B |
|---|
| element | pure substance that cannot be broken down into simpler substances by chemical or physical means. Each element has unique physical and chemical properties. |
| compound | a pure substance made up of atoms of 2 or more different elements joined together by chemical bonds. |
| mixture | a combination of 2 or more subtances that are not chemically combined. Not a pure subtance. |
| pure substance | a sample of matter, either a single element or a single compound, that has definite chemical and physical properties. |
| physical change | a change of matter from one form to another without a change in chemical properites -- such as a state change, dissolving, crushing, bending, cutting, etc. |
| chemical change | a change that occurs when materials are changed by the making or breaking of chemical bonds into new substances with new properties. |
| law of conservation of matter/mass | matter cannot be created or destroyed; in a chemical reaction, this means that the number and type of atoms in the reactants must equal the number and type of atoms in the products |
| atom | smallest unit of an element that still has the properties of that element |
| molecule | smallest unit of a compund that still has the properties of that compound; at least 2 atoms bonded together |
| solution | homogenous mixture of 2 or more substances; example: salt-water |
| dissolving | the process in which particles of substances separate and spread evenly throughout a mixture |
| homogenous mixture | a mixture with all parts evenly mixed throughout; it looks like on substance |
| heterogenous mixture | a mixture that is very unevenly mixed, different parts of the mixture are visible |
| products | in a chemical reaction, the compounds or elements that are produced by the reaction |
| reactants | in a chemical reaction, the compounds or elements that enter into the reaction |
| mass | amount of matter in an objects, measured in grams or kilograms |
| flammability | a chemical property that describes how well a material reacts to burn with oxygen |
| solubility | a physical property that describes how well a material dissolves into another material |
| characteristic property | a physical or chemical property that can be used to identify a substance; it does not vary with the amount of the substance; ex: boiling point, ,flammability, solubility |
