The freezing point of a substance is the temperature at which it changes from a liquid to a solid state. It is the temperature at which the vapor pressure of the solid and the liquid phases are equal and the substances exist in equilibrium. The freezing point is a characteristic property of a substance and can be used to identify and purify it.
Develop and use models of Earth’s interior composition to illustrate the resulting magnetic field (e.g., magnetic poles) and to explain its measureable effects (e.g., protection from cosmic radiation).