| A | B |
| physical property | a property that can be observed without changing what a substance is made of |
| physical change | a change in a substance's appearance but not in what it is made of |
| chemical property | a property that describes how a substance reacts with other substances |
| chemical change | a change that forms new substances with new properties |
| element | one of the 109 basic substances of matter |
| nucleus | the central part of an atom |
| electron | a negatively charged atomic particle |
| neutron | a particle with no charge found in the nucleus of an atom |
| proton | a positively charged particle in the nucleus of an atom |
| conductor | a material that transmits heat or electricity |
| periodic table | arrangement of all known elements in a chart in order of the number of protons each element has |
| formula | a way to write the kinds and numbers of atoms in a molecule or compound |
| symbol | one or two letters that stand for the name of an element |
| solution | a mixture of molecules made by dissolving one substance in another substance |
| solvent | a substance that dissolves a solute |
| solute | a substance that dissolves another substance |
| dilute | containing a small amount of solute |
| concentrated | containing a large amount of solute |
| suspension | a mixture in which patricles of a substance are scattered in another substance but not dissolved |