What term is used to describe substances that can be mixed together?

The term used to describe substances that can be mixed together is "miscible." This indicates that two or more liquids can blend smoothly and uniformly to form a solution, meaning that they can exist together without separating. For example, water and alcohol are miscible because they can combine in any proportion without forming distinct layers.

In contrast, "immiscible" refers to substances that do not mix; for instance, oil and water are immiscible because they separate and do not form a uniform solution. "Insoluble" pertains to solids that cannot dissolve in a solvent, while "permeable" describes a material that allows fluids or gases to pass through it. These terms highlight different properties of substances in relation to their ability to mix or dissolve.