[tamubsa]

Why does Kr boil at a lower temperature than Ca? The intermolecular forces in both are dispersion (unless they are metal in Ca?), so I thought I would determine this by molar mass. Since Ca has a lower molar mass, I assumed it would have the lower boiling temperature. Is it because Ca is a metal?

P.S. My final is in 2 hours so help would be very much appreciated .

[Hunter2]

Krypton is a noble gas what has no reaction to itself or others, so the boiling temperature is very low. A metal like Calcium has still some bonds to other atoms.