Hardness in groundwater is due to the presence of metal ions. True or False

False

Explanation:

Water hardness in most groundwater is due to a natural occurrence caused by the weathering of limestone, sedimentary rock and calcium bearing minerals. Hardness can also occur locally in groundwater from chemical and mining industry effluent or excessive application of lime to the soil in agricultural areas.

Limestone is not a metallic element or metallic alloy, although it does contain the metallic element calcium, it is not formed by the same processes as metals are.