If a substance changes state of matter (e.g., liquid to gas), then this is a physical change because the original properties of the substance have not changed.
B
If a substance undergoes a physical change, then it will retain most of its original properties because no new substance is formed.
C
If a substance undergoes a chemical change, then it will not retain its original properties because a new substance is formed.
D
If a precipitate is formed when two substances are mixed, then a chemical change has taken place because precipitates are new substances.