How is Charles's Law defined in terms of temperature and volume?

Charles's Law states that the volume of a gas is directly proportional to its absolute temperature when the pressure is held constant. This means that as the temperature of a gas increases, its volume also increases, provided that the pressure does not change. The relationship is mathematically expressed as V ∝ T, which can also be written as V/T = k, where k is a constant for a given amount of gas at constant pressure. This positive correlation occurs because, at higher temperatures, the kinetic energy of the gas molecules increases, causing them to move more vigorously and occupy a larger volume.

In contrast, other options address incorrect relationships or conditions that do not apply to Charles's Law. For example, the idea that volume is inversely proportional to absolute temperature directly contradicts the fundamental premise of the law. Likewise, asserting that volume remains unaffected by temperature or relates directly to pressure describes different gas behaviors that are governed by separate gas laws, such as Boyle's Law or the ideal gas law, but not Charles's Law.