Answer: New molecules formed.
Step-by-step explanation:
A physical change is defined as the change in which shape, size will be altered. No new substance gets formed in these reactions.
A chemical change is defined as the change in which chemical composition is altered. A new substance is formed in these reactions.
The substance changed shape is a physical change.
The substance froze means the state is changed and is a physical change.
The substance changed size is a physical change.
Thus when new molecules are formed, it is a chemical change.