Across
- 3. The capital of Japan. (5)
- 5. The longest river in the world. (4)
- 6. An eight-sided polygon. (7)
- 9. The capital of Australia. (8)
- 11. The planet known as the "Red Planet." (4)
- 12. The scientific study of life. (7)
- 13. A group of stars, gas, and dust held together by gravity. (6)
- 14. A large, flat, elevated area of land. (8)
- 16. The process of water evaporating from plants. (13)
- 17. The collective term for the bones of the human body. (8)
- 20. A measure of how hot or cold something is. (11)
Down
- 1. The largest organ in the human body. (4)
- 2. A form of government in which power is held by the people. (9)
- 4. A device used to see very distant objects. (9)
- 7. The force that pulls objects toward the center of the Earth. (7)
- 8. The process by which plants make their own food. (14)
- 10. The chemical symbol for gold. (2)
- 15. The layer of the atmosphere closest to Earth. (11)
- 18. A word that describes a noun. (9)
- 19. The process of breaking down food into simpler substances. (9)