Across
- 2. Chemically combined
- 3. Anything that has mass or takes up space
- 4. Cu
- 5. Center of an atom
- 7. Consists of 1 kind of atom
- 8. Chemical Formula
- 9. Smallest unit of matter
Down
- 1. Components that can not be observed separately
- 3. Physically combined
- 6. Components that can be observed separately