The technique used to remove ions from hard water is called:

Correct answer: Water Softening. Water softening removes calcium and magnesium ions (the cause of hardness) from water.

Background: A common method is ion exchange.

• Filtration: Filtration removes solid particles.
• Distillation: Distillation removes almost all impurities but is not the usual technique for removing hardness.
• Chlorination: Chlorination kills germs.

Did you know? Hard water does not form lather easily with soap.

Memory trick: Hard water → soften.