H-O bond is a covalent polar bond, also O is more electronegative than H, so
The oxygen atom in water molecule has
a partial negative charge.
Two charged atoms. This is because the atom that loses the electron will become a positively charged ion (a cation) and the one that gains that electron will become a negatively charged ion ( an anion).
Freezing point depression is directly proportional to molality. So the compound to have the greatest effect will be the one that disassociates into the most ions = CaF2
it never will, it will pop