Question

Why does diamond have a high melting point?

Answer 1

Hint : Diamond is a solid form of carbon that has its atoms organised in a diamond cubic crystal structure. Another solid form of carbon known as graphite is the chemically stable form of carbon at ambient temperature and pressure, although diamond nearly never transforms to it. Diamond has the highest hardness and thermal conductivity of any natural substance, qualities that make it ideal for cutting and polishing equipment in industry. They're also why diamond anvil cells may expose materials to pressures encountered deep down.

Complete Step By Step Answer:
In diamond, each carbon atom is covalently linked to four other carbon atoms. Separating the atoms takes a lot of energy. This is due to the strength of covalent bonds. This is why diamonds have such a high melting point. All of Diamond's carbon atoms are reported to have strong chemical connections with the four other carbon atoms, forming a flawless tetrahedron structure throughout the crystal. The carbon atoms are hybridised, and the carbon-carbon atom bond lengths are equivalent. Diamond develops a three-dimensional network of strong covalent connections as a result of this.
The molecular structure of diamond is massive. Covalent bonds exist between each carbon atom and four other carbon atoms. Separating the atoms in diamond takes a lot of energy. This is due to the fact that covalent bonds are extremely strong, and diamond includes a large number of them. As a result, the melting and boiling points of diamond are extremely high.

Note :
Diamond has an ignition temperature of $690{\text{ }}^\circ C$ to $840{\text{ }}^\circ C$ in a pure oxygen environment; smaller crystals tend to burn more quickly. It heats up from red to white heat and burns with a faint blue flame, continuing to burn even after the heat source is withdrawn. In contrast, because oxygen is diluted with nitrogen in air, combustion will stop as soon as the heat is removed. Any imperfections will be left as ash when a clear, perfect, transparent diamond is totally transformed to carbon dioxide. A cigarette lighter or the heat created from cutting a diamond will not ignite the diamond, but home fires and blow torches will.