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.
London forces are the only interaction that exist between all species, including ions, polar molecules, and nonpolar molecules. London interactions between polar molecules is usually stronger than their dipole-dipole interactions. This can be seen in the trend in boiling points in HCl, HBr, and HI.