Across
- 3. A small body that orbits around a larger one
- 6. A large body of water surrounded by land
- 7. A word that has the same meaning as another word
- 9. The process by which plants make their food
- 10. The smallest unit of an element
- 11. A line that divides a circle into two equal parts
- 14. A book containing words and their meanings
- 15. A measurement of how hot or cold something is
- 16. The study of past events through remains and artifacts
- 18. Mammal known for its black and white stripes
- 19. A machine that converts mechanical energy into electrical energy
Down
- 1. A structure that holds back water
- 2. A group of planets that orbit around a star
- 4. A type of rock that forms from magma
- 5. The force that pulls objects towards the center of the Earth
- 7. A device that measures the Earth's shaking during an earthquake
- 8. A system of government by the whole population
- 11. A long period without rain
- 12. A reptile with a hard shell
- 13. A type of energy that comes from the movement of particles
- 17. The process of turning a liquid into a gas