Across
- 2. Number average atomic mass
- 3. a negative electrical charge
- 5. the small part of a chemical element
- 6. doesn't conduct electricity or heat
- 7. central part of an atom
- 8. a horizontal row on the periodic table
Down
- 1. a positive electrical charge located in the nucleus
- 2. nonmetallic elements
- 4. Gasses group of 18 of the periodic table
- 6. a neutral electrical charge located in the nucleus