text: The formation of Langmuir monolayers by adsorption onto a surface dramatically reduces the entropy of the molecular system.
  To find the entropy decrease, we find the entropy of the molecule when in the adsorbed condition.
  Using Stirling's approximation, we have
  On the other hand, the entropy of a molecule of an ideal gas is
  where  is the thermal de Broglie wavelength of the gas molecule.