| A | B |
|---|
| Mass | A measure of the amount of matter in an object. |
| Matter | Anything that has mass and takes up space. |
| Weight | A measure of how gravity pulls on an object. |
| Volume | A measure of how much space the matter of an object takes up. |
| Density | The amount of matter in a certain volume of a substance; found by dividing the mass of an object by its volume. |
| Buoyancy | The upward push of a liquid or gas on an object placed in it. |
| Electron | A particle in the space outside the nucleus of an atom that carries one unit of negative electric charge. |
| Element | A pure substance that cannot be broken down into any simpler substances through chemical reactions. |
| Metal | Any of a group of elements that conducts heat and electricity, has a shiny luster, and is flexible. |
| Atom | The smallest unit of an element that has the properties of that element. |
| Nucleus | The center of an atom that has most of its mass. |
| Proton | A particle in the nucleus of an atom that carries one unit of positive electric charge. A non-feeding stage in complete metamorphosis in which a hard, caselike cocoon surrounds the organism. |
| Neutron | A particle in the nucleus of an atom that has no electric charge. |
| Molecule | A particle that contains more than one atom joined together. |
