| A | B |
|---|
| Atomic Number | The number of protons in the nucleus of an atom |
| Atomic Mass | The sum of the numbers of protons and neutrons in the nucleus of an atom |
| Valence electron | An electron that is found in the outermost shell of an atom and that determines the atom’s chemical properties |
| Chemical Change | A change that occurs when a substance changes composition by forming one or more new substances |
| Physical Change | A change in matter from one form to another without a change in chemical properties |
| Pure Substance | This is a sample of matter, either a single element or a single compound, that has definite chemical and physical properties |
| Mass | This is a measure of the amount of matter in an object |
| Density | This is the ratio of the mass of a substance to the volume of a substance |
| Element | This is a substance that cannot be separated or broken down into simpler substances by chemical means |
| Mixture | This is a combination of two or more substances that are not chemically combined |
| Compound | This a substance made of atoms of two or more different elements that are chemically combined. |
| Charge | This is the property of certain subatomic particles that determines their electromagnetic interaction |
| Electron | This is a subatomic particle that has a negative charge |
| Nucleus | This is an atom’s central region which is the most dense region of an atom. |
| Neutron | This is a subatomic particle that has no charge and that is found in the nucleus of an atom |
| Proton | This is a subatomic particle that has a positive charge and that is found in the nucleus of an atom |
| Dependent Variable | This is what you measure in the experiment and what is affected during the experiment. |
| Independent variable | A variable that does not depend on another |
