What type of water contains calcium and magnesium salts?

The correct answer is hard water. Hard water is characterized by the presence of significant amounts of dissolved minerals, primarily calcium and magnesium salts. These minerals are often leached from the earth as water flows through soil and rock formations. When water contains high levels of these salts, it results in hard water, which can have various effects on household appliances, plumbing, and even the taste and quality of drinking water.

Soft water, in contrast, has low concentrations of calcium and magnesium salts and is often treated to remove these minerals for ease of use in household chores and for improving the efficacy of soaps and detergents. Distilled water is water that has been purified through the process of distillation, effectively removing minerals and impurities, resulting in minimal or no calcium and magnesium salts. Tap water varies in hardness depending on the source and treatment but is not categorized specifically as hard or soft without additional information. Thus, hard water is definitively the type that contains significant amounts of calcium and magnesium salts.