Why doesn't a covalent bond conduct electricity?

The correct choice indicates that covalent bonds do not conduct electricity primarily because they do not allow electrons to move freely. In a covalent bond, atoms share electrons to achieve stability. This sharing creates localized electron pairs that are bound within the molecules and do not move freely throughout the material. Consequently, since the electrons are not free to flow, which is necessary for electrical conduction, substances that are held together by covalent bonds typically act as insulators rather than conductors.

The nature of covalent bonding means that the resulting compounds can form strong structures, but this strength comes at the cost of electron mobility. In contrast, metals, which tend to conduct electricity well, have a different type of bonding—metallic bonding—where electrons are more mobile and can move freely, allowing for electrical conductivity. Thus, the inability of covalent compounds to conduct electricity is intimately linked to the fixed positions of their shared electrons.