A pure substance is made of one type of element or compound and a mixture is made up of two or more pure substances. Water is a compound but it is classified as a homogeneous mixture but it is not a mixture. I don't understand can I please have an explanation? Why can a homogeneous mixture be a pure substance or a mixture, when a pure substance is not a mixture?

Explanation:homogeneous mixtures may be considered examples of pure substances. Examples of homogeneous mixtures include vegetable oil, honey, and air. While these substances contain multiple types of molecules, their composition is consistent throughout a sample. "This is how its considered pure "

Mixtures, on the other hand, are considered impure substances. A mixture is created when substances combine but no chemical reaction occurs. In general, a mixture can be separated into its original components, while a pure compound cannot

"This is how its considered as not pure"