| A | B |
|---|
| Compounds | Substance made up of two or more elements chemically combined. |
| Periodic table | Display of the elements in order of their atomic number. |
| Molecule | The smallest complete unit of a compound that has all the properties of that compound. |
| Element | A substance that cannot be broken down into a simpler substance by ordinary means. |
| Liquid | State of matter that has no defined shape but a definite volume and flows very easily. |
| Atomic number | A number that is unique to each element of the periodic table; also equals the number of protons. |
| Solid | State of matter that has a definite size |
| Subatomic-particle | Particles that are smaller than an atom. |
| Neutron | Subatomic particle found inside the nucleus that has mass but does not have a charge. |
| Atom | The smallest part of an element that contains all the properties of that element. |
| Gas | State of matter characterized by lacking a specific shape and volume and can greatly contract or expand due to changes in pressure and/or temperature; it will evenly disperse in a container. |
| Matter | Anything that takes up space and has mass. |
| Electron | Negatively-charged subatomic particle that is found outside the nucleus. |
| Proton | Subatomic particle that is found inside the nucleus and has mass and a positive charge |
| Atomic mass | It is approximately the sum of the number of protons and neutrons found in the nucleus of an atom. |
