Avogadro's law ?

Avogadro's law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules. This means that the volume of a gas is directly proportional to the number of moles of gas present. In other words, as the number of moles of gas increases, the volume of the gas also increases proportionally. This law is based on the concept that gases are made up of individual particles that are in constant motion and have negligible volume compared to the volume of the container they are in.