| A | B |
|---|
| nucleus | core or center of the atom |
| proton | positive charge; inside nucleus |
| electron | negative charge; outside of nucleus |
| neutron | NO charge; neutral; inside nucleus |
| periodic table | organizes elements by increasing atomic number |
| compound | two or more substances chemically combined |
| chemical bonds | hold atoms together in a molecule |
| element | a substance that can't be broken down into simpler substances by physical or chemical means |
