Across
- 4. Differences among individuals in a population
- 7. Substance made of only one type of atom
- 9. Early stage in a star’s formation
- 13. Exploding massive star at the end of its life
- 14. Type of reproduction producing identical offspring
- 17. Variety of species in an ecosystem
- 19. Process where atoms rearrange
- 20. Layer of gases surrounding Earth
- 21. Smallest unit of an element
- 22. Caused by uneven heating of Earth’s surface
Down
- 1. A rotating storm system with low pressure
- 2. Plants converting light to chemical energy
- 3. Amount of matter in an object
- 5. Trait that helps organisms survive
- 6. Breaks down dead organisms
- 8. Large system of stars, gas, and dust
- 10. Cloud of gas and dust where stars form
- 11. Drives energy for weather and climate
- 12. Warming of Pacific Ocean affecting weather
- 15. Gradual change in ecosystems over time
- 16. Our home galaxy
- 18. Levels in a food chain