A student makes several observations about a piece of iron

Subject : Chemistry

Question: A student makes several observations about a piece of iron. Which observation describes a chemical property of the iron?

A. Its mass is 52 grams.

B. Its density is 7.9 grams/centimeter3.

C. It rusts when exposed to air.

D. It conducts electricity.

Expert Verified Solution:

The correct answer is:

C. It rusts when exposed to air.

Explanation:

A chemical property describes a substance’s ability to undergo a specific chemical change. When iron rusts upon exposure to air, it reacts with oxygen and moisture to form iron oxide, a new substance. This is a chemical change, indicating a chemical property of iron.

In contrast:

A. Its mass is 52 grams and B. Its density is 7.9 grams/centimeter³ are physical properties because they describe measurable characteristics of the iron that do not involve a chemical change.

D. It conducts electricity is also a physical property because it describes a characteristic (electrical conductivity) that does not involve a change in the chemical composition of the iron.

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