Answer:
B. Does the substance corrode when left in water?
Explanation:
The scientist in this question is concerned about a chemical property of the substance in question. Changing the shape of the substance or determining the color of the substance or finding the melting point of the substance although all useful in learning more about the substance, are all physical properties of the substance. Corrosion on the other hand is chemical reaction. That is the one test that tells the scientist more about chemical properties of the substance.