Evaluate the physical properties of potassium, magnesium, and copper. Select the best choice to use for a building project. Explain why this metal is the best building material to use.

Answer: Copper is the best choice to be used in a building project.

Explanation: We are given three elements and asked which of them can be used as a building material.

Potassium is most reactive amongst the given elements. It can be easily oxidized in the presence of water. Copper is the least reactive and hence will not get oxidize easily.

Potassium and magnesium, both are soft and can be cut easily with knife but copper is hard and can't be cut easily with knife.

Density of potassium and magnesium are less than water and are light weight elements, but copper has high density than water.

From the above properties, it is suitable to use copper as a material in building project.