Across
- 3. negative electricity
- 10. breaks down formula
- 11. positive electrons
- 14. atoms attract shared electrons
- 17. electrons share atoms
- 18. an substance that has mass
- 19. species of atoms
- 20. positively charged ion
- 21. attraction between atoms, ions, or molecules
- 22. natural gas
- 23. two or more elements
- 24. outer shell
Down
- 1. undergoes change during a reaction
- 2. a group of atoms bonded together
- 4. sharing electrons between two atoms
- 5. same element different neutrons
- 6. species formed by chemical reactions
- 7. basic unit of a chemical element
- 8. energy stored in chemical bonds
- 9. atom or molecule
- 12. negatively-charged ion
- 13. atoms come close together
- 14. released after chemical reaction
- 15. reversible chemical reaction
- 16. attraction between opposed ions