- A heterogeneous mixture has a non-uniform composition where different components can often be seen or separated. - A homogeneous mixture (solution) has a uniform composition throughout. - Hydrochloric acid (HCl in water), vinegar (acetic acid in water), and soda water (CO₂ in water) are all solutions, meaning the solute is dissolved at a molecular level, forming homogeneous mixtures. - Milk is an emulsion of fat globules and proteins dispersed in water. While it may appear homogeneous, these particles are large enough to scatter light (Tyndall effect) and are not dissolved at a molecular level, making it heterogeneous.