Which of the following describes a physical property of copper metal? At high temperatures, copper forms a black copper oxide. Copper slowly oxidizes to form a green patina, like that on the Statue of Liberty. Copper metal is ductile. It can be pulled into thin wires. Copper does not react with water.
The Correct Answer and Explanation is:
Correct Answer: Copper metal is ductile. It can be pulled into thin wires.
Explanation
Physical properties are characteristics of a substance that can be observed or measured without changing the substance’s chemical identity. These include properties such as color, density, melting point, boiling point, malleability, ductility, electrical conductivity, and hardness. They describe how a substance is, rather than how it reacts with other substances.
In this case, “Copper metal is ductile. It can be pulled into thin wires.” describes a physical property. Ductility refers to a material’s ability to be stretched into a wire without breaking, and it is a common physical property of metals, including copper. This characteristic does not involve any change in the chemical composition of the copper. The copper remains chemically the same before and after it is drawn into wires.
The other statements describe chemical properties, which are characteristics that describe a substance’s ability to undergo a chemical change:
- “At high temperatures, copper forms a black copper oxide.” – This involves a reaction with oxygen at elevated temperatures and results in the formation of a new substance, copper oxide, indicating a chemical change.
- “Copper slowly oxidizes to form a green patina, like that on the Statue of Liberty.” – This also describes a chemical reaction between copper, oxygen, carbon dioxide, and water, forming copper carbonate or copper sulfate compounds on the surface.
- “Copper does not react with water.” – Although this describes a lack of reactivity, it is still a chemical property because it pertains to copper’s behavior in a potential chemical reaction.
Therefore, among the choices given, only the statement about copper being ductile clearly and correctly identifies a physical property of copper.
