[Complete Sentence Required] If the plates are solid and the mantle is liquid, why do the plates not sink into the mantle, explain your thinking

Explanation:

because thats what I put and got it right

Yes  

Explanation:

The jar with cold milk is less hot than the jar with hot milk. The temperature of the milk is a measure of its "hotness".

You must add heat to cold milk to make it hot. The jug of hot milk has more internal energy than the jug of cold milk.