A mixture of argon and neon has a measured gas density of 1.66 g / L at STP. Assuming ideal‑gas behavior, what is the average molar mass of the mixture?

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms