Across
- 4. not responding situation
- 5. the mass of the element
- 6. number of protons in the nucleus
- 11. an expression that shows the compound of an element
- 12. solid
- 13. either a liquid or gas
- 14. most important part of an object
- 15. combining atoms
Down
- 1. arranged in rows and groups
- 2. atom with neutral charge
- 3. One of the four principal conditions in which matter exists
- 7. atom with positive charge
- 8. acting in response to a situation rather than creating or controlling it.
- 9. atom with negative charge
- 10. gases like helium-neon and argon
- 11. letters on an element