Across
- 3. a form of exothermic reaction that produces both light and heat
- 5. the way chemists and physicists organize the elements
- 8. often produces light and heat
- 13. the number of protons in an element
- 15. building blocks of the universe
- 16. alkali _____
- 17. subatomic particle that has a negative charge
- 18. subatomic particle without a charge
Down
- 1. the mass of an atom of any given element
- 2. changes form but not properties
- 4. a group of 2 or more atoms held together by chemical bonds
- 6. a group of metals that react violently with water
- 7. can be easily separated
- 9. uses light and heat to function
- 10. subatomic particle with a positive charge
- 11. reaction produces light and heat
- 12. not a metal
- 14. 2 substances that are unable to easily be separated