On a heating curve a plateau corresponds to A) a change in temperature of a liquid. B) a change in temperature of a solid. C) a change in temperature of a gas. D) a change of state. E) the solid being broken into smaller pieces.

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