1. Chapter 17 Section 4 heterogeneous mixture- not uniform in composition, can pick out individual pieces Types of Heterogeneous Mixtures 1)suspension -mixture from which particles settle out upon standing ex- dirt and water -can filter out to separate *particle size ≈100nm -compare to solutions

2. 2)colloid -mixture in which the particles are spread throughout the dispersion medium, they do not settle -dispersion medium = solvent -dispersed phase = solute -cannot be filtered ex- glue, jello, paint, smoke, fog, dust in air *particle size in intermediate between solution and suspensions→ between 1nm and 100nm

3. -Colloid and suspension particles exhibit the: Tyndall Effect- scattering of visible light in all directions ex- headlights in fog, sunbeam in dusty room Why do solutions not exhibit Tyndall Effect? -b/c the particles are too small Brownian motion- chaotic movement of colloidal particles -caused by collisions of solute and solvent particles which prevent settling

4. emulsions- colloidal dispersions of liquids in liquids ex- soap in greasy water