Avogadro's law (sometimes referred to as Avogadro's hypothesis or Avogadro's principle) is a gas law which states that, under the same condition of temperature and pressure, equal volumes of all gases contain the same number of molecules.
Avogadro's law (sometimes referred to as Avogadro's hypothesis or Avogadro's principle) is a gas law. Equal volumes of all gases contain the same number of molecules. This is under the same condition of temperature and pressure. This is what this gas law states.