Which property would you expect for a material with a three-dimensional covalent network and no free electrons?

Which property would you expect for a material with a three-dimensional covalent network and no free electrons?

• A. High electrical conductivity
• B. Poor electrical conductivity
• C. Conducts only when molten
• D. Conducts in solid state and gas state

Answer: (B)

Electrical conductivity comes from charge carriers that can move. In a three-dimensional covalent network, atoms are held together by strong covalent bonds in a rigid lattice, and the electrons are largely involved in those bonds rather than roaming freely. Without mobile charge carriers, electric current can’t flow easily, so the material acts as a poor conductor. That’s why the expected property is poor electrical conductivity. In contrast, high conductivity would require free electrons or ions, and a material like this wouldn’t suddenly become conductive just because it’s melted, since there aren’t free ions to move. It also wouldn’t conduct in solid and gas states.

Electrical conductivity comes from charge carriers that can move. In a three-dimensional covalent network, atoms are held together by strong covalent bonds in a rigid lattice, and the electrons are largely involved in those bonds rather than roaming freely. Without mobile charge carriers, electric current can’t flow easily, so the material acts as a poor conductor. That’s why the expected property is poor electrical conductivity.

In contrast, high conductivity would require free electrons or ions, and a material like this wouldn’t suddenly become conductive just because it’s melted, since there aren’t free ions to move. It also wouldn’t conduct in solid and gas states.