Why does diamond have a high melting point?

Answer 1

Melting point is the temperature required to break the intermolecular bonds between molecules of a substance. This means that the bonds such as hydrogen bonds and polar attraction between the individual molecules of a substance must be broken so that the molecules can flow past each other in a liquid state. Diamonds have a very high melting point. This is because diamond is a macromolecule. Diamond is made up of single carbon bonds, with four carbons attached to each carbon molecule. In contrast, molecules such as water and carbon dioxide have a set number of atoms per molecule, and that number is very low. There are no intermolecular forces between diamonds molecules, so in order for diamond to become liquid the actual carbon bonds have to be broken.

This property of diamond makes it have a very high melting point. As heat is given to diamond, the energy is transferred throughout the molecule and dispersed by the huge number of bonds in diamond. It takes a very high melting point to finally break carbon bonds of a diamond molecule. Once carbon bonds begin breaking due to the extremely high heat, the molecules begins to melt.

Answer 2

In a diamond every carbon shares all 4 of its available electrons with other carbon atoms so it consists of 8 carbon atoms, forming a tetrahedral network. This network is very strong and rigid, thus the diamond is hard and has a high melting point.