Charles's law indicates that as temperature increases, what happens to 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 the gas rises, the volume it occupies also increases. This behavior occurs because, at higher temperatures, gas molecules move faster and spread apart more, leading to an expansion of volume.

Therefore, when the temperature increases, the gas molecules have more kinetic energy, causing them to collide with the walls of the container more forcefully and frequently, resulting in an increase in volume. Hence, the correct statement is that volume expands as temperature rises. This principle is fundamental in thermodynamics and is critical in various applications, including in hot air balloons and internal combustion engines, where understanding the behavior of gases under temperature changes is essential for efficient operation.