Final answer:
Gravity has the greatest influence at large scales, such as the interaction between planets, while the electric force dominates at the small scale, such as within atoms where it influences the behavior of charged particles.
Step-by-step explanation:
The influence of gravity and the electric force depends on the scale we are observing. Gravity has the greatest influence at a large scale, such as between celestial bodies like the Earth and the Sun. This is because gravity is always attractive and affects all objects with mass, regardless of their electric charge. On a small scale, such as between elementary particles, the electric force (electrostatic force) is much more significant. For instance, the electrostatic force holds together the proton and electron in a hydrogen atom, and it is also responsible for most everyday interactions involving charged particles. Unlike gravity, the electric force can be both attractive and repulsive, which is why it is critical in bonding atoms and molecules.
The gravitational force is proportional to the mass of the objects and inversely proportional to the square of the distance between them. The electric force, while also inversely proportional to the square of the distance, depends on the charges of the interacting particles. Thus, on an atomic scale where charged particles interact, the electric force is much stronger than the gravitational force. However, with large masses like planets and stars, gravity tends to dominate because most objects are nearly electrically neutral, leading to a near cancellation of Coulomb forces.