Across
- 4. Doing something with the least waste of energy or time.
- 6. A smart guess or idea you can test in an experiment.
- 9. Speed in a specific direction.
- 10. A temperature scale used in most countries and in science.
- 13. Heat energy that comes from inside the Earth.
- 15. A good guess or close answer based on known information.
Down
- 1. The process of breaking down dead things into smaller parts.
- 2. A math sentence showing that two things are equal.
- 3. Related to movement or motion.
- 5. A temperature scale mostly used in the U.S.
- 7. Process plants use to make food from sunlight and air.
- 8. The amount of matter in an object (not the same as weight).
- 11. A natural resource that can be used again and again.
- 12. Symbols or letters that stand for unknown values in math.
- 14. A force that slows things down when they rub together.