Answer
See explanation
Work Step by Step
Silicon carbide (SiC) is a covalent compound with a crystal structure resembling a diamond lattice. It consists of silicon (Si) atoms bonded to carbon (C) atoms in a tetrahedral arrangement, forming a network of strong covalent bonds.
Proposed Structure of SiC
Crystal type:
SiC crystallizes in a tetrahedral lattice.
Each Si atom is covalently bonded to 4 C atoms, and each C atom is bonded to 4 Si atoms, forming a 3D network.
This is analogous to diamond, where each C is tetrahedrally bonded to 4 C atoms, but here the lattice alternates Si and C atoms.
Bonding:
All bonds are strong covalent bonds (Si–C).
This network is responsible for SiC’s extreme hardness, high melting point, and chemical stability.
Polymorphs:
SiC exists in many polytypes (different stacking sequences of Si–C layers), e.g., 3C-SiC (zinc blende structure), 4H-SiC, and 6H-SiC.
Diagram (schematic, tetrahedral) (see graph)
Each Si is tetrahedrally bonded to 4 C atoms, and each C to 4 Si atoms.
This extends infinitely in 3D.
