The correct option is **B. Surface tension leads to the formation of a spherical shape for the droplet in the absence of other forces.** ### Detailed Explanation: 1. **Understanding Surface Tension:** - Surface tension is a physical property of liquids that arises from the cohesive forces between liquid molecules. Molecules at the surface of a liquid experience a net inward force because they are attracted to other liquid molecules but not to air molecules above them. This creates a "skin" on the surface of the liquid, which tends to minimize the surface area. 2. **Formation of a Spherical Shape:** - In the absence of external forces (like gravity or adhesion to a surface), a droplet of liquid will naturally form a shape that minimizes its surface area. The shape that achieves this is a sphere. This is because a sphere has the smallest surface area for a given volume. Therefore, surface tension causes the droplet to adopt a spherical shape to minimize energy. 3. **Role of Other Forces:** - While surface tension is the primary factor in determining the shape of a droplet, other forces can influence this shape when the droplet is in contact with a solid surface. For example, adhesive forces between the liquid and the solid can cause the droplet to spread out rather than remain spherical. However, the question specifies the behavior of a droplet in the absence of other forces, reinforcing that surface tension alone leads to a spherical shape. ### Why Other Options Are Incorrect: - **Option A: Surface tension causes the droplet to spread out evenly across the surface.** - This statement is incorrect because surface tension does not cause spreading; rather, it tends to keep the droplet compact. If the droplet spreads, it is due to adhesive forces between the liquid and the surface, not surface tension. - **Option C: Surface tension has no effect on the shape of the droplet.** - This is incorrect because surface tension is the primary reason for the droplet's shape. Without surface tension, the droplet would not maintain a cohesive form and would not be able to resist external forces. - **Option D: Surface tension only affects the volume of the droplet, not its shape.** - This statement is misleading. Surface tension does not affect the volume directly; rather, it influences the shape of the droplet. The volume remains constant, but the shape is determined by surface tension, which seeks to minimize the surface area. ### Summary of Key Points: - Surface tension is a property that causes liquid molecules to attract each other, leading to a minimized surface area. - In the absence of external forces, a liquid droplet will form a spherical shape due to surface tension. - Other forces, such as adhesion to surfaces, can alter the droplet's shape but are not considered in this context. - Understanding surface tension is crucial for predicting the behavior of liquids in various scenarios, including droplets on surfaces. This thorough understanding of surface tension and its effects on droplet shape is essential for mastering concepts in fluid mechanics and related fields in physics.