Water Is Life

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.

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.