Oil and water can form a stable dispersion with the help of a third substance commonly called

Oil and water can form a stable dispersion with the help of a third substance commonly called an emulsifier (or emulsifying agent).

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• Explanation: Oil and water are immiscible because of polarity differences. An emulsifier has two parts: a hydrophilic (water-loving) head and a hydrophobic (oil-loving) tail. This dual nature allows it to reduce the interfacial tension and stabilize the oil droplets in water (or vice versa), preventing them from separating.

 Final Answer: The third substance is called an emulsifier.