Quadrupling the distance between two charges results in a significant decrease in the electrostatic force between them, specifically by a factor of 16. This phenomenon is explained by the inverse-square law, which states that the force is inversely proportional to the square of the distance. Therefore, as the distance increases, the electrostatic force diminishes exponentially. When the distance is doubled, the force decreases to a quarter of its original value, highlighting the law's impact. Understanding this principle is essential for analyzing electrostatic interactions.