Question

Graphite is soft while diamond is hard because:

• A. graphite is in powder form
• B. diamond has $s{p}^2$ hybridization but graphite has $s{p}^3$ hybridization
• C. graphite is in planar form while diamond is in tetrahedral form
• D. graphite is covalent and diamond is ionic

Answer 1

Answer: (C)

In diamond each carbon atom is $s{p}^3$ hybridized and is joined to each by strong covalent bonds and form tetrahedral structure. In graphite carbon is $s{p}^2$ hybridized. The carbon atoms join each other to form planar, hexagonal sheet like structure held together by weak van der Waal force. Therefore, diamond is harder than graphite.