The diagram shows three containers, each filled with a different gas - Leaving Cert Chemistry - Question d - 2021

According to Avogadro's law, equal numbers of molecules (or moles) occupy equal volumes at the same temperature and pressure. Therefore, the quantities of gases in each container are the same in terms of moles. However, CO₂ is a triatomic molecule, meaning each molecule is composed of three atoms. Thus, the CO₂ container has more atoms compared to the other two gases.