Which term refers to minerals such as calcium and magnesium that contribute to water hardness?

Which term refers to minerals such as calcium and magnesium that contribute to water hardness?

• A. Solids
• B. Hardness
• C. Gas
• D. pH

Answer: (B)

Hardness is the term for dissolved minerals, mainly calcium and magnesium, that give water its hard character. These multivalent ions come from rocks and stay in solution, leading to scale buildup and reduced soap effectiveness. The other options don’t describe minerals that cause hardness: solids is too broad, gas isn’t involved here, and pH measures acidity/alkalinity rather than mineral content. In practice, hardness is often expressed as calcium carbonate equivalents and helps determine treatment needs like softening or scale control.

Hardness is the term for dissolved minerals, mainly calcium and magnesium, that give water its hard character. These multivalent ions come from rocks and stay in solution, leading to scale buildup and reduced soap effectiveness. The other options don’t describe minerals that cause hardness: solids is too broad, gas isn’t involved here, and pH measures acidity/alkalinity rather than mineral content. In practice, hardness is often expressed as calcium carbonate equivalents and helps determine treatment needs like softening or scale control.