If the pressure of a gas is held constant, how does the volume relate to the temperature according to Charles' Law?

According to Charles' Law, if the pressure of a gas is held constant, the volume of the gas is directly proportional to its temperature when measured on an absolute scale (Kelvin). This means that as the temperature of the gas increases, the kinetic energy of the gas molecules also increases, causing them to move more vigorously and occupy a larger volume.

Conversely, when the temperature decreases, the kinetic energy of the molecules decreases, leading to a reduction in the volume they occupy. Therefore, the relationship stipulated by Charles' Law is that an increase in temperature results in an increase in volume, which is why the correct answer highlights this direct relationship. This principle is fundamental in thermodynamics and helps explain various phenomena in everyday situations, such as the inflation of a balloon when heated.