| A | B |
|---|
| chemistry | the study of matter and changes in matter. |
| physical property | a property of matter that can be directly observed or measured without changing the composition of the substance being observed. |
| chemical property | properties of matter that are observable when the substance undergoes a chemical change. |
| atom | the smallest particle that retains the characteristic composition of an element. |
| element | a substance that cannot be broken down into simpler substances by chemical means. |
| electron | a negativly charged subatomic particle |
| proton | positivly charged particle located in the nucleus |
| neutron | a subatomic particle that has no charge . |
