Atomic theory formula for the water molecule (HO), or 16 if one assumes the modern water formula (HO). The flaw in Dalton's theory was corrected in principle in 1811 by Amedeo Avogadro. Avogadro had proposed that equal volumes of any two gases, at equal temperature and pressure, contain equal numbers of molecules (in other words, the mass of a gas's particles does not affect the volume that it occupies). Avogadro's law allowed him to deduce the diatomic nature of numerous gases by studying the volumes at which they reacted. For instance: since two liters of hydrogen will react with just one liter
Zeroth law of thermodynamics that provides a continuous ordering of states. The dimensionality of a surface of constant temperature is one less than the number of thermodynamic parameters, thus, for an ideal gas described with three thermodynamic parameters "P", "V" and "N", it is a two-dimensional surface. For example, if two systems of ideal gases are in equilibrium, then = where "P" is the pressure in the "i"th system, "V" is the volume, and "N" is the amount (in moles, or simply the number of atoms) of gas. The surface = constant defines surfaces of equal thermodynamic temperature, and one may label defining "T"