Answer :
Answer:
**C) Surface tension**
Surface tension is the primary force that causes a water droplet to form a spherical shape. It arises from the cohesive forces between the molecules at the surface of the water. These forces pull the molecules at the surface inward, minimizing the surface area of the droplet, which naturally leads to a spherical shape, as a sphere has the smallest possible surface area for a given volume.
Here's why the other options are less relevant in this context:
- **A) Viscosity:** While viscosity affects the flow of liquids, it does not significantly influence the shape of a water droplet in free fall.
- **B) Air resistance:** This can distort the shape of a falling droplet, especially if it falls from a great height or if it's moving at high speeds. However, in the absence of significant air resistance, surface tension dominates the droplet's shape.
- **D) Temperature:** Temperature can affect surface tension to some extent, but it is not the primary factor determining the spherical shape of a water droplet.
Explanation:
