Question

Write two examples of covalent solids.

Answer 1

Hint: A chemical compound or an element in which atoms or molecules are bonded by covalent bonds and are in a continuous network extending throughout the material is known as Covalent solids.

Complete step by step answer:
-A solid material regularly ordered arrays of components, that is the atoms, molecules, or ions are aligned in a highly ordered microscopic structural unit, forming a regular and symmetrical crystal lattice that extends in every direction is known as a crystal or a crystalline solid.
-Crystalline solids based on types of particles present and the type of chemical bonding that takes place between the particles are of four types of crystals:
(i) Ionic
(ii) Metallic
(iii) Covalent network
(iv) Molecular

-Covalent solids are also known as a network solid or covalent network solid.
-The typical examples of crystal solids are diamond, graphite, silicon dioxide, or quartz.
-Let us now see the important features of a diamond.Diamond is known for its highest hardness and thermal conductivity nature than any other natural material. Carbon has an atomic number of 6 and electronic arrangement as 2,4. In diamond, each carbon atom shares electrons with four other carbon atoms forming four single bonds.
-Let us now see some of the features of graphite as the second example. Graphite is a crystalline form of the elemental carbon with the atoms being arranged in a hexagonal structure that looks like a stack of layers that have the distance as about 2.5 times the distance between the atoms within each layer. . Graphite is the most stable, naturally occurring form of carbon under standard conditions. Graphite under high pressures and temperatures converts to diamond.

Note: Covalent solids have some general properties. First is the hardness. They are very hard due to the presence of strong covalent bonds throughout the crystal lattice. Second is their high melting point due to the presence of strong covalent bonds. The third is their solid-phase electrical conductivity. Depending on the nature of the bonding present between the networks, some network solids have all the electrons used for sigma bonds and thus no delocalized electron available. Therefore they are poor conductors of electricity. Fourth is solubility. Crystal solids are generally insoluble in any solvent.