Across
- 3. A type of pollution where human activity changes water temperature, altering oxygen levels and harming aquatic life.
- 8. A quantitative scale used to measure how acidic or basic a water sample is.
- 9. The property of a liquid's surface that allows it to resist an external force, letting insects walk on water.
- 14. A non-living component of an aquatic ecosystem, like water or temperature.
- 16. The variable that a scientist deliberately changes or manipulates during an investigation.
- 17. An overgrowth of algae caused by excess nutrients (like nitrates or phosphates) from human runoff.
- 18. Mineral compounds often found in fertilizers and detergents that can cause nutrient pollution in local waterways.
- 20. A measurement of water clarity or how cloudy the water is due to suspended particles.
Down
- 1. The primary federal law governing water pollution in the United States.
- 2. The physical geographic feature where the vast majority of Earth’s freshwater is locked up and unavailable for direct human use.
- 4. A physical or behavioral trait that allows an organism to survive in its specific aquatic environment.
- 5. A factor in an experiment that a scientist purposely keeps the same to ensure a fair test.
- 6. The variable in an experiment that is observed or measured; it changes in response to the independent variable.
- 7. The small number in a chemical formula that shows how many atoms of an element are present.
- 10. A pure substance consisting entirely of one type of atom that cannot be broken down simpler.
- 11. The living or once-living parts of an ecosystem that interact with abiotic factors.
- 12. The total amount of dissolved salts in a water sample.
- 13. A molecule with an uneven distribution of electrical charge, making one end slightly positive and the other negative.
- 15. A substance made of two or more different elements chemically bonded together (e.g., H₂O).
- 19. An area of land where all of the water that falls in it drains off into a common outlet or local body of water.