Development of the Modern Freezer. Bacteria are usually the cause of food decay, but they can't grow as well or at all in freezing temperatures, which are at 32 degrees Fahrenheit (0 degrees Celsius) or lower.
HF- polar molecule: dipole-dipole forces. There are also dispersion forces and H bond between HF. BF3- nonpolar: dispersion forces. Ar- Dispersion forces between Ar atoms.
However, you notice an anomaly; HF should have a boiling point below that of HCl, then how come it has the highest boiling point? After all, Fluorine has lesser electrons than Chlorine and hence should have lesser London dispersion forces between them. This is true but there is another reason behind that: Hydrogen Bonding.