| A | B |
| matter | Anything that has mass and takes up space |
| atom | The smallest particle of matter |
| proton | A subatomic particle with a positive charge. |
| neutron | A subatomic particle with no charge |
| electron | A subatomic particle with a negative charge |
| nucleus | The center of an atom that conatins both protons and neutrons |
| electron cloud | Surrounds the nucleus and contains electrons |
| element | A substance such as oxygen that cannot be broken down into a simpler form. |
| isotopes | Are formed when atoms of the same element differr in the number of neutrons |
| atomic number | The number of protons in each atom of an element |
| mass number | The number of protons and neutrons in the nucleus of an atom. |
| compound | These are formed when two are more elements are chemically bonded |
| covalent bonds | These are formed when 2 or more elements share electrons |
| ionic bonds | when ions from different elements bond to form a compound |
| solution | A mixture in which the substances are universally combined. |