general properties of colloids
colloidal particles are so small that their surface area in ralation to mass is very large
electrical properties all colloidal particles are electrically charged if electrodes from a d.c. source are placed in a collodial dispersion the particles migrate towards the pole of opposite charge
collodial particles are in constant motion because of bombardment by molecules of dispersion medium this motion is called brownian motion named after robert brown who first noticed it