The principle of cleaning by soap is

Options

A. surface tension
B. floatation
C. viscosity
D. elasticity

Explanation

**Step-by-Step Solution:**

1. **Understanding Soap Structure**: Soap molecules have a unique structure with a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. This dual nature allows soap to interact with both water and oils/grease.

2. **Formation of Micelles**: When soap is added to water, the soap molecules arrange themselves into spherical structures called micelles. The hydrophobic tails of the soap molecules face inward, trapping grease and dirt, while the hydrophilic heads face outward, interacting with water.

3. **Reduction of Surface Tension**: Soap reduces the surface tension of water. This reduction allows water to spread and penetrate more easily into fabrics and surfaces, facilitating the removal of dirt.

4. **Emulsification of Grease**: The micelles encapsulate grease and dirt, effectively emulsifying them. This means that the dirt and grease can be suspended in water, allowing them to be rinsed away easily.

5. **Cleaning Action**: When rinsing with water, the micelles, along with the trapped dirt and grease, are washed away, resulting in clean surfaces or fabrics.

**Final Principle Statement**: The principle of cleaning by soap involves the formation of micelles that encapsulate dirt and grease, reducing the surface tension of water, and allowing for the emulsification and removal of these impurities.

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