The critical constants and orthobaric densities of xenon

Rudorf, in a paper on the rare gases and the equation of state, has drawn attention to the high value found by Ramsay and Travers for the density of liquid xenon at its boiling point. As is well known the atomic volume in any group of elements in the periodic table either increases regularly with rise of atomic weight or remains approximately constant, so that it is to be expected that the atomic volume of xenon would be greater than of krypton, since the value for krypton exceeds that of argon. If Rudorf's calculated value for the density of neon is taken into account, this anomaly becomes more striking, as is shown from the following table taken from his paper:-