Liquids that are not capable of being mixed into stable solutions are considered what?

Liquids that are not capable of being mixed into stable solutions are referred to as immiscible. This term describes a situation where two substances do not combine to form a homogeneous mixture, resulting instead in distinct layers or phases. For example, oil and water are two substances that do not mix well; when combined, they separate into two layers rather than forming a uniform solution.

In contrast to immiscible liquids, the other terms refer to different properties of mixtures. Homogeneous liquids would maintain a uniform composition throughout, while miscible liquids can mix evenly in any proportion. Emulsified refers to a mixture where two immiscible liquids are combined with the help of an emulsifying agent, yet they remain distinct and separate at the microscopic level without the emulsifier. Hence, for liquids that do not mix and remain separate, the correct terminology is indeed immiscible.