| A | B |
|---|
| matter | substance that physical objects are composed of |
| atom | smallest particle of an element |
| pure substance | matter that always has the same composition |
| element | a substance that cannot be broken down into simpler substances |
| compound | a substance made from two or more simpler substances |
| mixture | its properties can vary because the composition is not fixed |
| homogeneous | so evenly distributed that it appears to contain only one substance |
| heterogeneous | parts are noticeably different from one another |
| suspension | heterogeneous mixture that separates into layers over time |
| colloid | mixture that contains some particles that are intermediate in size (between the small particles in a solution and the larger particles in a suspension) |
| solution | when substances dissolve and form a homogeneous mixture |
| ion | an atom or group of atoms with a positive or negative charge |
| molecule | neutral group of atoms joined together by one or more covalent bonds |
| filtration | process that separates materials based on the size of their particles |
| distillation | process that separates the substances in a solution based on their boiling points |
| physical property | any characteristic of a property that can be observed or measured without changing the composition of its substances |
| density | ratio of a material's mass to its volume |
| viscosity | tendency of a liquid to keep from flowing |
| conductivity (electrical) | material's ability to allow electrical charges to flow |
| conductivity (thermal) | material's ability to allow heat to flow |
| malleability | ability of a solid to be hammered without shattering |
| hardness | resistance of a mineral to scratching |
| melting point | temperature at which a substance changes from solid to liquid |
| boiling point | temperature at which a substance boils |
| buoyancy | ability of a liquid to exert an upward force on an object placed in it |
| chemical property | any property that produces a change in the composition of matter |
| flammability | material's ability to burn in the presence of oxygen |
| reactivity | property that describes how readily a substance combines chemically with other substances |
| chemical change | changes that occurs when a substance reacts and forms one or more new substances |
| physical change | change that occurs when some properties of a material change, but the substances in the material stay the same |
| precipitate | solid that forms and separates from a liquid mixture |
