# Deviation in compressibility factor in different gases [duplicate]

• See my answer here, which addresses this question almost exactly. The only thing to add is the same reasoning I applied for $\ce{H2}$ also applies to helium. Note that for both molecules there is actually a minimum, but they are extremely tiny and not observable on the scale of the plots you're referring to. – jheindel Nov 9 '17 at 19:21