Question

Arrange the following in decreasing order according to the number of linkages among silicon tetrahedra of soil particles:
(A). Nesosilicates,
(B). Phyllosilicates,
(C). Tectosilicates,
(D). Inosilicates

Choose the correct answer from the options given below:

• A. (A), (B), (C), (D)
• B. (C), (B), (D), (A)
• C. (B), (A), (D), (C)
• D. (A), (B), (D), (C)

Hint:

Remember the order of sharing: Tecto (all 4 shared) \(\gt\) Phyllo (3 shared) \(\gt\) Ino (2 shared) \(\gt\) Sorosil (1 shared) \(\gt\) Neso (0 shared).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Silicate minerals are classified based on how their silicon-oxygen tetrahedra (\(\text{SiO}_4^{4-}\)) share oxygen atoms (linkages) to form different structural arrangements.

Step 2: Detailed Explanation:
The number of oxygen linkages per tetrahedron for each group is:
- Tectosilicates (C): Form a 3D framework where all 4 oxygen atoms are shared, giving 4 linkages per tetrahedron.
- Phyllosilicates (B): Form 2D sheets where 3 oxygen atoms are shared, giving 3 linkages per tetrahedron.
- Inosilicates (D): Form single or double chains where 2 (or occasionally 2.5) oxygen atoms are shared, giving 2 linkages per tetrahedron.
- Nesosilicates (A): Form independent tetrahedra where 0 oxygen atoms are shared, giving 0 linkages per tetrahedron.
Arranging these in decreasing order of linkages yields: Tectosilicates (C) \(\gt\) Phyllosilicates (B) \(\gt\) Inosilicates (D) \(\gt\) Nesosilicates (A).

Step 3: Final Answer:
The correct decreasing order is (C), (B), (D), (A).