Across
- 3. An element in group 7 that is used to kill microorganisms
- 7. The general term for the removal of slat from water
- 11. pH 7 on the pH scale - the pH of pure water
- 12. Water that is safe to drink
- 13. (2 words) The test for pure water
Down
- 1. Aluminium sulfate is added to clump smaller particles together which sink
- 2. Removal of large items from the water
- 4. Contains only a single substance
- 5. Boiling, evaporating and condensing salt water to obtain the fresh water
- 6. When water is passed through sand to remove small particles
- 8. Larger particles of mud sink and settle out of the water
- 9. (2 words) Using pressure to push water molecules through a membrane leaving the salt behind
- 10. When microorganisms e.g. bacteria are killed