Question

Graphite and diamonds are made up of carbon atoms. Graphite, however, is soft and can be used to write with while diamonds are the hardest substance known to man and are the only substance that can be used to cut other diamonds. What is the main reason for this difference?

• A. The carbon atoms in graphite are covalently bonded while the carbon atoms in diamonds are ionicly bonded.
• B. The bonds within a layer of graphite are relatively strong but the bonds between the layers of graphite are relatively weak.The bonds between the carbon atoms of a diamond are relatively strong throughout the entire structure.
• C. The bonds within the layers of a graphite are relatively weak, allowing for the atoms to slide past each other.The bond between the atoms in diamond have a limited capacity to slide.
• D. Graphite is held together by covalent bonds while diamond is held together by Londong Dispersion Forces.

Answer 1

The correct option is C The bonds within the layers of a graphite are relatively weak, allowing for the atoms to slide past each other.The bond between the atoms in diamond have a limited capacity to slide.

Property of chemical elements to exist in two or more different forms but in the same physical state is known as Allotropy. Graphite and Diamond are allotropes of carbon. Diamond is sp3 hybridized having a strong covalent bond between the atoms and has a tetrahedral structure thereby reducing the ability to slide. Whereas, graphite being sp2 hybridized is in the form of the hexagonal ring which is held by weak van der Waals forces. Thus, it can slide easily.