Question

This lab question is: How can you distinguish a physical change from a chemical change?

Which statements below are an appropriate hypothesis in response to this question? Check all that apply.
a) 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.

Answer 1

Physical changes involve a change in state of matter, while chemical changes result in the formation of new substances.

Step-by-step explanation:

To distinguish between a physical change and a chemical change, you can look at several factors. In physical changes, the substance may change its state of matter (e.g., liquid to gas), but the original properties of the substance remain the same. However, in chemical changes, the substance undergoes a change in its chemical composition, resulting in the formation of new substances.

For example, if a precipitate is formed when two substances are mixed, it indicates a chemical change because precipitates are new substances. Therefore, the appropriate hypotheses are:

• 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.
• If a substance undergoes a chemical change, then it will not retain its original properties because a new substance is formed.
• If a precipitate is formed when two substances are mixed, then a chemical change has taken place because precipitates are new substances.