| A | B |
|---|
| mass | amount of matter in an object |
| Density | mass per unit volume of a substance |
| element | substance consisiting of only one type of atom |
| mixture | composed of two or more substances |
| matter | anything that has mass and occupies space |
| volume | how much space something takes up |
| Atom | The smallest object that retains properties of an element |
| Proton | Particle found in a nucleus with a positive charge |
| Neutron | A particle found in the nucleus of an atom |
| Nucleus | The central part of an atom that contains the protons and neutrons |
