Across
- 2. Mass divided by volume.
- 5. A pure substance of one atom type.
- 9. What snowshoes increase to reduce pressure.
- 11. Used to reduce friction, like oil or grease.
- 12. The total of protons and neutrons in an atom.
- 14. A positively charged particle in atoms.
- 15. The energy we feel from the Sun.
- 17. The invisible force between charged objects.
Down
- 1. The path a planet takes around a star.
- 3. The star at the center of our Solar System.
- 4. A negatively charged particle in atoms.
- 6. The center of an atom.
- 7. How much matter an object has.
- 8. The force that happens when two surfaces rub.
- 10. Force divided by area.
- 13. Anything that has mass and takes up space.
- 16. Our home planet, supports life.