Diamond and graphite are both crystalline forms of carbon
CHEMISTRY · Single correct · CBSE · Chemistry · Carbon and its Compounds · Carbon and its Compounds
Problem
Diamond and graphite are both crystalline forms of carbon. Which explanation best accounts for the fact that diamond is rigid and hard whereas graphite is soft and can be used as a lubricant?
(a) Diamond contains ionic bonds between its carbon atoms, whereas the bonds within graphite are covalent and therefore weaker and able to slide.
(b) Diamond is a three-dimensional network of covalent bonds, whereas graphite consists of two-dimensional sheets held together by weak intermolecular forces.
(c) Diamond’s rigidity is due to delocalized π electrons that glue the lattice in place, while graphite lacks such delocalization.
(d) Carbon atoms in diamond are sp2-hybridized, forming strong double bonds in all directions, whereas the sp3 bonds in graphite are weaker and easily cleaved.