Question

Diamond and graphite are the covalent compounds of carbon element (C).
(A) True
(B) False

Answer 1

Carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb) are the elements of group 14 elements named carbon family. Out of these elements, carbon is the seventeenth most abundant element by mass in the earth’s crust. Carbon is widely distributed in nature and also in a combined state.

Complete step by step answer:
Carbon forms many allotropic forms in an elemental state as both crystalline and amorphous. Diamond and graphite are two crystalline forms of carbon.
Diamond: it has a crystalline lattice and each carbon atom in diamond undergoes $s{{p}^{3}}$ hybridization and is linked to the other four carbon atoms by hybridizing orbitals in a tetrahedral structure. So, all carbon atoms in diamond are bonded with covalent bonds and the C-C bond length is 154pm. Hence, Diamond is a covalent compound of carbon (C).
Graphite: this is layer like structure, which is held by van der Waals force and the distance between two layers is 340 pm. Each layer is hexagonal planar rings of carbon atoms and the C-C bond length within the layer is 141.5 pm. Each carbon atom in graphite undergoes $S{{p}^{2}}$ hybridization and makes 3 $\sigma$ bonds with 3 neighboring carbon atoms and one $\pi$ bond.
Hence, from the above discussion, diamond and graphite are covalent compounds of carbon (C).
So, the correct answer is “Option A”.

Note: Diamond has a three-dimensional structure involving strong C-C covalent bonds, which requires more energy to break these bonds. So, the melting point of the diamond is high. Because $\pi {{e}^{-}}$ are delocalized in graphite, which conducts electricity and graphite cleaves easily between the layers caused to use as a lubricant.