Milk is an example of:

The correct answer is option 4.

Key Points

• Milk is an emulsion, meaning it is a colloidal mixture of two immiscible liquids:
  • Fat globules (dispersed phase)
  • Water (dispersion medium)
• In emulsions, one liquid is finely dispersed in another with the help of an emulsifying agent (in milk, casein protein acts as the emulsifier). Hence, option 4 is correct.

Additional Information

• Sol: A sol is a colloidal system where a solid is dispersed in a liquid (e.g., paint, ink).
• Aerosol: A colloidal system where a liquid or solid is dispersed in gas (e.g., fog, deodorant spray).
• Foam: A colloidal system where gas is dispersed in a liquid or solid (e.g., whipped cream, shaving foam).