| A | B |
|---|
| element | A substance that cannot be split into a simpler substance; determined by the number of protons. |
| atom | The smallest particle of an element. |
| proton | A positively charged subatomic particle that has a mass of 1. Protons are found in the nucleus of the atom. |
| neutron | A subatomic particle with no electric charge that is found in the nucleus of the atom. |
| electron | A negatively charged subatomic particle which moves around the nucleus of an atom. |
| compound | A substance made of two or more elements chemically combined in a specific ratio or proportion. |
| solid | One of four phases of matter which has a definite shape and volume. |
| liquid | One of four phases of matter which has volume and takes the shape of the container it is in. |
| gas | One of four phases of matter which does not have a definite shape or volume. |
| plasma | One of four phases of matter which is very rare and present in the sun. |
