The correct option is **A. Electrostatic forces can be both attractive and repulsive, while gravitational forces are always attractive.** ### Detailed Explanation 1. **Understanding Electrostatic Forces:** - Electrostatic forces arise from the interaction between charged particles. There are two types of charges: positive and negative. - When two like charges (both positive or both negative) are brought close to each other, they repel each other. Conversely, when a positive charge and a negative charge are near each other, they attract each other. - This dual nature (attraction and repulsion) is a fundamental characteristic of electrostatic forces. 2. **Understanding Gravitational Forces:** - Gravitational forces, on the other hand, are always attractive. They arise from the mass of objects and the gravitational interaction between them. - No matter the configuration of masses, they will always attract each other. For example, the Earth attracts the Moon, and the Moon attracts the Earth, but they never repel each other. 3. **Why Option A is Correct:** - The key difference highlighted in option A is accurate because it captures the essence of how these two forces operate. Electrostatic forces can either pull objects together or push them apart, depending on the nature of the charges involved. In contrast, gravitational forces can only pull objects together. ### Why the Other Options are Incorrect or Weaker **B. Gravitational forces are significantly stronger than electrostatic forces at all distances.** - This statement is misleading. While gravitational forces are indeed very weak compared to electrostatic forces at small distances (like the scale of atoms), they become significant over astronomical distances. However, at the atomic and molecular levels, electrostatic forces dominate. Thus, this statement is not universally true. **C. Electrostatic forces only act on charged particles, while gravitational forces act on all masses regardless of charge.** - While it is true that electrostatic forces act only on charged particles, the statement does not highlight a key difference in the nature of the forces themselves. It merely states a fact about the conditions under which each force operates. The essence of the difference lies more in the attractive/repulsive nature of the forces rather than the types of particles they act upon. **D. Both forces follow an inverse square law, but electrostatic forces have a greater range than gravitational forces.** - This statement is incorrect. Both electrostatic and gravitational forces indeed follow an inverse square law, meaning that the force decreases with the square of the distance between the two objects. However, the range of both forces is theoretically infinite; they both diminish with distance but do not have a defined limit. Therefore, this option is misleading. ### Summary of Key Points for Revision - **Electrostatic forces can be attractive or repulsive**, depending on the charges involved, while **gravitational forces are always attractive**. - **Electrostatic forces dominate at small distances**, while **gravitational forces become significant over larger distances**. - Both forces follow an **inverse square law**, but their strengths and behaviors differ significantly based on the nature of the interacting entities (charge vs. mass). - Understanding the fundamental differences in the nature of these forces is crucial for solving problems in physics related to fields, forces, and interactions.