The Principal Cations in Hard Water Are Sodium and Potassium

Q25: A stagnant pond has an odor like

Q26: Many communities are beginning to use sludge

Q27: All of the following atoms are found

Q28: Soft water contains relatively large concentrations of<br>A)iron

Q29: Fluorides are added to water to<br>A)kill viruses.<br>B)remove

Q31: Acid rain results in the release of

Q32: The saltiness of the oceans is<br>A)decreasing slowly.<br>B)increasing

Q33: Lakes and streams with granite rock bottoms

Q34: Pathogenic is<br>A)disease-causing.<br>B)an antibiotic.<br>C)a cure for a disease.<br>D)a

Q35: The water cycle acts to purify water