Which giant covalent structure conducts electricity?

Which giant covalent structure conducts electricity?

• A. Graphite
• B. Diamond
• C. Silicon Dioxide
• D. None of these

Answer: (A)

Electrical conduction in a giant covalent lattice happens when some electrons are not fixed to a single atom and can move through the structure. Graphite has this feature. Its carbon atoms stack into flat layers with hexagonal patterns. In each layer, carbon forms three strong covalent bonds with neighbors, using three of its four valence electrons. The remaining electron becomes delocalised, creating a pool of electrons that can move freely within the layer. These delocalised electrons carry charge and enable electricity to flow along the layers. The layers are held together only by weaker forces, which explains graphite’s softness, but the crucial point for conductivity is the presence of those mobile electrons. In contrast, diamond has a rigid three-dimensional network where each carbon is bonded to four others, leaving no delocalised electrons to move and carry charge. Silicon dioxide also forms a strong covalent network with no free electrons, so it does not conduct. That’s why graphite is the correct choice.

Electrical conduction in a giant covalent lattice happens when some electrons are not fixed to a single atom and can move through the structure. Graphite has this feature. Its carbon atoms stack into flat layers with hexagonal patterns. In each layer, carbon forms three strong covalent bonds with neighbors, using three of its four valence electrons. The remaining electron becomes delocalised, creating a pool of electrons that can move freely within the layer. These delocalised electrons carry charge and enable electricity to flow along the layers. The layers are held together only by weaker forces, which explains graphite’s softness, but the crucial point for conductivity is the presence of those mobile electrons.

In contrast, diamond has a rigid three-dimensional network where each carbon is bonded to four others, leaving no delocalised electrons to move and carry charge. Silicon dioxide also forms a strong covalent network with no free electrons, so it does not conduct. That’s why graphite is the correct choice.