Across
- 4. mass the mass of an atom of a chemical element
- 5. the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms
- 6. shows energy levels of atoms
- 11. the system of electrons surrounding the nucleus of an atom
- 12. table a row is called a period on the
- 14. the basic unit of a chemical element.
- 15. protons and neutron make up the
Down
- 1. has negative energy
- 2. chemical substance composed of many identical molecules
- 3. water
- 7. hard state of matter
- 8. has 0 energy
- 9. made the periodic table
- 10. number tells you with the element is
- 12. has positive energy
- 13. what is oxygen