| Tyndall Effect | Light scattering, path visible | Particle size comparable to light wavelength | Distinguishes colloid from true solution |
| Brownian Motion | Continuous zig-zag particle movement | Unequal molecular bombardment | Keeps particles suspended (kinetic stability) |
| Electrophoresis | Particle migration in electric field | Charged particles move to opposite electrode | Demonstrates colloidal charge; used in purification |
| Coagulation | Settling/aggregation of particles | Charge neutralization by electrolyte/electric field | Can be deliberate (water treatment) or avoided (colloid stabilization) |
| Protective Colloid Action | Lyophilic colloid prevents lyophobic coagulation | Adsorption of lyophilic colloid on lyophobic particle | Used in photography, ice cream, pharmaceuticals |
| Dialysis | Removal of small molecules via semi-permeable membrane | Diffusion of small particles through membrane | Purification of colloids; kidney function (hemodialysis) |