What is typically used to blend or mix two substances together?

A solvent is a substance that dissolves a solute, resulting in a solution. It typically facilitates the blending or mixing of two substances together by breaking down the solute's molecular structure, allowing for a uniform mixture. This characteristic is especially useful in various applications, including skincare formulations and cosmetic products, where achieving a consistent texture and homogeneity is crucial.

In contrast, metals, gases, and compounds do not serve primarily as blending agents. Metals can undergo physical mixing but are not utilized for dissolving other substances in the same way solvents do. Gases can also mix with other substances, but they do not perform the same role as solvents in creating solutions. Lastly, compounds are formed when two or more elements are chemically bonded together. They are not used to blend substances but rather are the end result of chemical reactions, which may involve solvents during their formation. Hence, a solvent is the correct choice for blending or mixing two substances together effectively.