Question

The basic structural unit of silicates is

• A. SiO^-
• B. \(SiO^{4-}_4\)
• C. \(SiO^{2-}_3\)
• D. \(SiO^{2-}_4\)

Answer 1

The Correct Option is B

The question asks for the basic structural unit of silicates. To answer this, let's explore the structure and nature of silicates:

Silicates are compounds containing silicon and oxygen, and they form a vital part of mineral chemistry in the Earth's crust. The fundamental building block of silicates is the silicate tetrahedron.

In a silicate tetrahedron, one silicon atom is surrounded by four oxygen atoms, forming a tetrahedral shape. The chemical representation of this tetrahedron is SiO^{4-}_4. Each oxygen carries a partial negative charge, leading to the overall negative charge on the tetrahedron. This unit can bond with other metal cations or share its oxygen atoms with adjacent tetrahedra, leading to a variety of complex structures.

Given the options:

• SiO^{-}
• SiO^{4-}_4
• SiO^{2-}_3
• SiO^{2-}_4

The correct answer is SiO^{4-}_4, which is the silicate tetrahedron, the most basic structural unit of all silicate minerals.

The other options do not accurately represent the basic silicate unit:

• SiO^{-}: Does not correspond to a basic silicate structure.
• SiO^{2-}_3: This does not form a standard tetrahedral structure in silicates.
• SiO^{2-}_4: Although closer, it still fails to represent the specific tetrahedral coordination of oxygen to silicon in a silicate unit.

Hence, the basic structural unit of silicates is correctly identified as SiO^{4-}_4.