Which principle describes the relationship between the pressure and volume of a gas at constant temperature?

Boyle's Law describes the inverse relationship between the pressure and volume of a gas when the temperature is held constant. This principle states that if the volume of a gas decreases, the pressure increases, provided the temperature does not change. Conversely, if the volume increases, the pressure decreases. This behavior is based on the idea that gas molecules collide with the walls of their container, and reducing the volume increases these collisions, leading to higher pressure.

In contrast, Charles' Law pertains to the relationship between volume and temperature, Avogadro's Law relates to the number of gas particles and volume, and Dalton's Law deals with the partial pressures of gases in a mixture. These principles address different aspects of gas behavior and do not describe the specific relationship focused on in the question.