Which statement is true regarding a good conductor?

• A. It has a full valence shell
• B. It has a low resistance
• C. It has no free electrons
• D. It cannot conduct electricity

Answer: (B)

A good conductor is characterized by its ability to allow electric current to flow through it with minimal resistance. This property is crucial in electrical applications, as it determines how easily electrons can move through the material. Metals, such as copper and aluminum, are excellent conductors due to their atomic structure, which enables the free flow of electrons when an electric field is applied. The phrase "low resistance" specifically refers to a material's capacity to oppose the flow of electric current; thus, materials that are good conductors typically exhibit low resistance, allowing for efficient energy transfer.

In contrast, having a full valence shell is associated with insulators or non-metals, which tend to hold their electrons tightly and do not conduct electricity well. The presence of free electrons is a hallmark of good conductors, as these free-moving charge carriers are essential for the conduction of electrical current. Lastly, a material that cannot conduct electricity is characterized as an insulator, which directly contradicts the defining qualities of a good conductor.