What kind of mixture is a marshmallow?

Marshmallows are a type of foam, which is a colloidal dispersion of gas bubbles in a liquid or solid. In the case of marshmallows, the gas bubbles are filled with air and the liquid is a sugar-based syrup. Marshmallows also contain gelatin, which is a protein that helps to stabilize the foam.

Overall, marshmallows are a mixture of solids, liquids, and gases, and can be classified as a colloidal foam.