The element carbon occurs in different forms in nature with widely varying physical properties. Both diamond and graphite are formed by carbon atoms, the difference lies in the manner in which the carbon atoms are bonded to one another. In diamond, each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure. In graphite, each carbon atom is bonded to three other carbon atoms in the same plane giving a hexagonal array. One of these bonds is a double-bond, and thus the valency of carbon is satisfied. Graphite structure is formed by the hexagonal arrays being placed in layers one above the other.
1. Forms of carbon are
(i) Diamond
(ii) Graphite
(iii) Buckminsterfullerene
(iv) All of these
2. Each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure in which form of carbon?
(i) Diamond
(ii) Graphite
(iii) Buckminsterfullerene
(iv) All of these
3. Each carbon atom is bonded to three other carbon atoms forming a rigid three-dimensional structure in which form of carbon?
(i) Diamond
(ii) Graphite
(iii) Buckminsterfullerene
(iv) All of these
4.Diamonds can be synthesised by subjecting pure carbon to very high -
(i) Pressure
(ii) Temperature
(iii) Both A and B
(iv) None of these
5. State true or false: The hardest substance known is Graphite.
(i) TRUE
(ii) FALSE
