In 1787, French scientist Charle (1746-1823) revealed that increasing the temperature of a gas by 1℃ at constant pressure increases the volume of the gas by 1/273 of the volume at 0℃. This is called Charle's law.
If the gas temperature is raised when the pressure is constant, the molecular motion is accelerated, and the number of collisions against the vessel wall increases, thereby increasing the volume of the gas. Conversely, lowering the gas's temperature slows the molecular motion and reduces the number of collisions against the vessel wall, reducing the volume of the gas. In other words, when the pressure is constant, when the temperature of the gas increases, the volume of the gas increases at a constant rate. At this time, the degree to which the volume of the gas changes is the same regardless of the type of gas.