Hardness of water is caused by the presence of ions of
Answer Details
The hardness of water is caused by the presence of ions of calcium and magnesium. These ions are typically found in the soil and rocks through which water flows, and they dissolve into the water as it passes through. When water is "hard," it means that it has a high concentration of these ions, which can cause issues with soap lathering, scaling in pipes and appliances, and other problems.