What is the translational kinetic energy of a Helium molecule (He) at 1500 K?
0.194 eV
Helium, at such high temperature, is a good example of a monoatomic ideal gas. All its internal energy will only be translational kinetic energy, related to the temperature as -
Internal energy = kinetic energy =32KBT.
=32×1.38×10−23×1500 J
=3.1×10−20 J
=(3.1×10−20)×(6.242×1018) eV
= 0.194 eV.