
Entropy Constants 309
Example 15.2: Solid Neon to its vapor via a liquid phase
As our next example we consider Neon with an atomic weight of M =20.18.
Neon is a rare earth element and these are very interesting elements. Neon is
a solid below its melting point of T
m
=24.6K. At this temperature, and 1 atm.
of pressure, it turns into a liquid but does not stay a liquid very long. Just a
few degrees higher, at T
b
=27.2K and again at one atmospheric pressure, it
turns into Neon gas. Firstly both the melting and boiling points are at rather
low temperatures. Secondly, the Debye temperature of solid Neon is 63K!The
reader should try to understand what it means ...