What properties result from a giant covalent structure like diamond?

What properties result from a giant covalent structure like diamond?

• A. Low melting point, conducts electricity.
• B. Soft; conducts electricity.
• C. Gaseous at room temperature.
• D. Very high melting point, hard, does not conduct electricity.

Answer: (D)

In a giant covalent structure such as diamond, each carbon atom forms strong covalent bonds to many neighbours in a continuous three‑dimensional network. Breaking into the lattice requires disrupting many bonds, so a lot of energy is needed to melt it, giving a very high melting point. Because all the electrons are tied up in those covalent bonds and there are no free moving electrons, it does not conduct electricity. The rigid, interconnected network also means there are no layers to slide past one another, making diamond extremely hard. So the properties you’d expect are a very high melting point, great hardness, and electrical non‑conductivity.

In a giant covalent structure such as diamond, each carbon atom forms strong covalent bonds to many neighbours in a continuous three‑dimensional network. Breaking into the lattice requires disrupting many bonds, so a lot of energy is needed to melt it, giving a very high melting point. Because all the electrons are tied up in those covalent bonds and there are no free moving electrons, it does not conduct electricity. The rigid, interconnected network also means there are no layers to slide past one another, making diamond extremely hard. So the properties you’d expect are a very high melting point, great hardness, and electrical non‑conductivity.