The freezing point of a solution the freezing point of the pure solvent

This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur.

Explanation:

Freezing Point Depression. The freezing point of a solution is less than the freezing point of the pure solvent. This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur

neutrons are in the middle of the atom and the electrons, which are much smaller.

pure substance: iron,copper

impure substance: water,charcoal