Covalent Network Solids Concepts

Covalent network solids are structures where atoms are bonded in a 3D network, like diamond, or in layers, like graphite. Diamond features carbon atoms in a tetrahedral arrangement, while graphite consists of graphene layers with weak van der Waals forces between them. These solids can be made of single or multiple elements, such as silicon carbide. They typically include carbon or silicon due to their four valence electrons, allowing for multiple covalent bonds. These solids are characterized by high melting points and rigidity, except for graphite, which is soft due to its layer structure. Covalent network solids are poor conductors but can be modified into semiconductors through doping.

What is the structural arrangement of carbon atoms in diamond?

• Planar

• Tetrahedral

• Hexagonal

• Linear

What type of forces exist between the layers of graphite?

• Hydrogen bonds

• Van der Waals forces

• Metallic bonds

• Ionic bonds

Which elements are typically found in covalent network solids?

• Hydrogen and Helium

• Iron and Copper

• Carbon and Silicon

• Oxygen and Nitrogen

What is the bonding arrangement in silicon carbide?

• Silicon bonded to four oxygens

• Silicon bonded to four carbons

• Silicon bonded to two carbons

• Carbon bonded to four silicons

Why do covalent network solids generally have high melting points?

• Because they are made of metals

• Due to weak intermolecular forces

• Due to ionic bonds

• Because of strong covalent interactions

What makes graphite soft compared to other covalent network solids?

• Weak van der Waals forces between layers

• Presence of metallic bonds

• High density of carbon atoms

• Strong covalent bonds within layers