A sample of graphite is exfoliated into single-atom-thick sheets known as graphene. Which property is most likely to increase appreciably as a direct result, and why?
a) Lubricity, because separate layers slide past one another even more readily when completely detached.
b) Melting point, because isolating each layer increases the number of σ bonds per carbon atom.
c) Electrical conductivity, because the absence of inter-layer interactions allows π electrons to move with fewer collisions.
d) Hardness, because removing cleavage planes leaves only strong in-plane covalent bonding.