Which of the following property of water can be used to explain the spherical shape of rain droplets ?

Options

A. Viscosity
B. Surface tension
C. Critical phenomena
D. Pressure

Answer

To determine which property of water explains the spherical shape of raindrops, we can analyze the given options step by step.

### Step 1: Understand the Properties
We have four properties to consider: viscosity, surface tension, critical phenomena, and pressure.

### Step 2: Analyze Viscosity
- **Definition**: Viscosity is the resistance of a liquid to flow. It describes how layers of liquid resist each other's movement.
- **Conclusion**: Viscosity does not influence the shape of raindrops, as it is related to the fluidity of the liquid rather than its shape.

### Step 3: Analyze Surface Tension
- **Definition**: Surface tension is a property of liquids that causes them to minimize their surface area. This is due to cohesive forces between liquid molecules.
- **Conclusion**: Since a sphere has the smallest surface area for a given volume, raindrops naturally take on a spherical shape due to surface tension. This property is indeed responsible for the spherical shape of raindrops.

### Step 4: Analyze Critical Phenomena
- **Definition**: Critical phenomena refer to the behavior of substances at critical points, involving critical temperature, pressure, and volume during phase transitions.
- **Conclusion**: This property does not relate to the shape of raindrops, as it deals with phase changes rather than the physical shape of liquids.

### Step 5: Analyze Pressure
- **Definition**: Pressure is the force exerted per unit area and is not a specific property of water.
- **Conclusion**: Pressure does not explain the shape of raindrops, as it is not a property that influences the liquid's form.

### Final Conclusion
The correct answer is **surface tension**, as it is the property of water that explains the spherical shape of raindrops.

---