1. what is hard water. 2. Mention four sources of water.
3. write down the chemical formula of water.
4. What is purification of water.
5. Mention two importance of purification of water.
6. Mention 4 method used ot purify water. 7. Mention 4 impurities found in water.
8. Explain the term contaminated of water.
9. State two physical properties of water. 10. mention the names of of the elements that causes hardness in water.​

Hno3(aq) → h+(aq) + no3−(aq). picture ii best represents the strong acid hno3. strong acids are strong electrolytes

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na