In graphite, electrons are free to move within the layers but not between layers. Which option is true?

• A. True
• B. False
• C. Sometimes true
• D. Not sure

Answer: (A)

Graphite conducts electricity mainly because its carbon atoms form flat sheets where the electrons are delocalized. Each carbon in a sheet is sp2-hybridized, making a strong in-plane network of sigma bonds, while the remaining p electrons form a pi system that spreads across the whole layer. These delocalized pi electrons are free to move within the sheet, giving good electrical conductivity along the layer.

Between the layers, the atoms are held together only by weak van der Waals forces, not by strong bonds. This arrangement means there isn’t a continuous path for electrons to move from one layer to another, so conductivity perpendicular to the layers is very low.

So the statement—electrons can move freely within the layers but not between them—aligns with graphite’s structure and its anisotropic conductivity.