Across
- 2. begins and ends with the same type of matter
- 5. something that is printed or published
- 8. happening earlier
- 9. by chance
- 11. physical change in which one state of matter changes to another
- 13. important
Down
- 1. begins with one kind of matter but ends with another
- 3. a printed list of questions used by researchers
- 4. rate; speed
- 6. change of a liquid to a gas without boiling
- 7. happening often; familiar
- 9. solid, brown substance formed when iron gets wet and reacts with oxygen in the air
- 10. turn down
- 12. black substance formed with silver reacts with sulfur in the air