Why is potable water not considered pure water?

Potable water is defined as water that is safe for human consumption, but it is not considered pure water because it contains dissolved substances such as minerals, salts, and other impurities that can come from natural sources, treatment processes, or the environment. Pure water would refer to H2O in its most unadulterated form, without any other substances present. Even though these dissolved substances in potable water are generally harmless or beneficial, they prevent it from being classified as "pure."

The other options suggest reasons that do not accurately reflect the definition of potable water. For instance, temperature does not influence whether water can be classified as pure or potable, nor does the source of the water, such as tap or bottled, inherently determine its purity. Also, while potable water can undergo chemical treatment, it is not the treatment itself that negates its classification as pure. Instead, it is the presence of dissolved substances that makes potable water a mixture rather than a pure compound.