Admission Test for Dental Hygiene (ATDH) Practice

Charles' Law specifically addresses the relationship between the volume of a gas and its temperature. It states that the volume of a gas is directly proportional to its absolute temperature (measured in Kelvin) when pressure is held constant. This means that if you increase the temperature of the gas, its volume will also increase, and conversely, if the temperature decreases, the volume will decrease as well.

This law can be mathematically expressed as V = kT, where V is the volume, T is the temperature in Kelvin, and k is a constant that relates the two variables. This direct proportionality highlights that when temperature increases, the gas molecules gain kinetic energy, causing them to move more and occupy a larger volume.

Options regarding pressure do not apply since they pertain to different gas laws, and stating that volume remains constant as temperature changes or decreases lacks the principle of direct proportionality that defines Charles' Law.