Which two substances are the main elements that make hard water?Group of answer choicesCalciumMagnesiumSodium

The two main elements that make up hard water are Calcium and Magnesium. Hard water is defined as water that has a high mineral content, specifically elevated levels of dissolved minerals, such as calcium (Ca²⁺) and magnesium (Mg²⁺) ions. These minerals enter water supplies through the leaching of rocks and soil, particularly limestone and dolomite, which are rich in calcium and magnesium carbonate.

When water flows over or through these geological formations, it dissolves these minerals, leading to the characteristic hardness of the water. The presence of these ions in water can lead to various issues, including scale buildup in plumbing, reduced soap effectiveness, and potential impacts on household appliances.

In summary, calcium and magnesium are the key contributors to water hardness, making them essential to understand when discussing water quality and treatment options.