Describe the cleansing action of detergents.

Explanation

We add detergent or soap to water, to remove the greasy dirt. Soap or detergent molecules have the shape of a hairpin. The head of hairpin shapes molecules to get attracted towards water surface and pointed ends of detergent molecules get attached to the molecules of grease. So a water - grease interface is formed. Due to this surface tension is decreased. The dirt is surrounded by detergents and then by water. When the clothes are rinsed in water, the greasy dirt is washed away by running water.