Across
- 1. A system of government where people vote
- 5. Shaking of the ground caused by tectonic movement
- 6. The layer of gases surrounding Earth
- 8. Reusing materials to reduce waste
- 12. Harmful substances added to the environment
- 13. When liquid water changes into gas
- 14. One of Earth’s large landmasses
- 15. A global network used for communication and information
- 17. The natural home of a plant or animal
- 18. The process of releasing energy from food
- 19. A tool used to find directions
- 20. Energy caused by moving electric charges
Down
- 2. An imaginary line that divides Earth into two halves
- 3. How hot or cold something is
- 4. A rocky object that orbits the Sun
- 7. Living and non-living things interacting in an area
- 9. A mountain that can erupt with lava
- 10. The force that pulls objects toward Earth
- 11. The process plants use to make food using sunlight
- 16. A tool used to see very small objects