Fifteen grams of a liquid plastic are frozen in a physical change that increases the volume. what can be known about the plastic after the change

It will still weigh the same, that is, 15 grams.

Explanation:

On the basis of the law of conservation of mass, mass can neither be destroyed nor be created, however, it can get changed from one form to another. Thus, during freezing of the liquid plastic, its molecules come close to each other, and as a consequence, it get modifies into solid-state.  

However, it will still be of similar weight as there will be no influence on its mass. Therefore, it can be said that plastic after getting transformed will still weigh fifteen grams.