Question

Which one of the following sequences of silicate structures indicates an increasing degree of sharing of corners of \( (\text{SiO}_4)^{4-} \) tetrahedra?

• A. Nesosilicate $\rightarrow$ Single-chain inosilicate $\rightarrow$ Phyllosilicate $\rightarrow$ Tectosilicate
• B. Tectosilicate $\rightarrow$ Phyllosilicate $\rightarrow$ Single-chain inosilicate $\rightarrow$ Nesosilicate
• C. Nesosilicate $\rightarrow$ Phyllosilicate $\rightarrow$ Single-chain inosilicate $\rightarrow$ Tectosilicate
• D. Single-chain inosilicate $\rightarrow$ Nesosilicate $\rightarrow$ Phyllosilicate $\rightarrow$ Tectosilicate

Hint:

In silicate structures, the degree of corner sharing increases as we move from isolated tetrahedra (nesosilicates) to a three-dimensional framework (tectosilicates).

Answer 1

The Correct Option is A

Step 1: Understanding the question.
The question asks for the correct sequence of silicate structures that indicates an increasing degree of sharing of corners of the \( (\text{SiO}_4)^{4-} \) tetrahedra. The degree of sharing of tetrahedral corners increases as we move from nesosilicates to tectosilicates.
Step 2: Analyzing the options.
(A) Nesosilicate \( \rightarrow \) Single-chain inosilicate \( \rightarrow \) Phyllosilicate \( \rightarrow \) Tectosilicate: Correct — This is the correct order, with nesosilicates having isolated tetrahedra, single-chain inosilicates having chains of tetrahedra, phyllosilicates having layers of tetrahedra, and tectosilicates having a three-dimensional framework of tetrahedra.
(B) Tectosilicate \( \rightarrow \) Phyllosilicate \( \rightarrow \) Single-chain inosilicate \( \rightarrow \) Nesosilicate: Incorrect — This sequence is reversed and does not represent an increasing degree of sharing of corners.
(C) Nesosilicate \( \rightarrow \) Phyllosilicate \( \rightarrow \) Single-chain inosilicate \( \rightarrow \) Tectosilicate: Incorrect — Phyllosilicates should not come before single-chain inosilicates in the correct order.
(D) Single-chain inosilicate \( \rightarrow \) Nesosilicate \( \rightarrow \) Phyllosilicate \( \rightarrow \) Tectosilicate: Incorrect — This sequence is not in the correct order of increasing sharing of tetrahedral corners.
Step 3: Conclusion.
The correct answer is (A) Nesosilicate \( \rightarrow \) Single-chain inosilicate \( \rightarrow \) Phyllosilicate \( \rightarrow \) Tectosilicate, as it accurately represents the increasing degree of corner sharing.