Question

Choose the correct option(s) that describe(s) the properties of clay minerals.

• A. Kaolinite is two-layered
• B. Illite is two-layered
• C. Montmorillonite is two-layered
• D. Montmorillonite swells in contact with water

Hint:

Clay minerals such as Kaolinite are two-layered, while Montmorillonite is known for its expandable layers that cause it to swell when in contact with water.

Answer 1

The Correct Option is A, D

Analyzing the Clay Mineral Structures
Option (A): This is correct because Kaolinite is a 1:1 type clay mineral with two layers: one tetrahedral sheet and one octahedral sheet.

Option (B): This is incorrect because Illite is a 2:1 type clay mineral with a structure that consists of two tetrahedral sheets sandwiching one octahedral sheet, not a two-layered structure.

Option (C): This is incorrect because Montmorillonite is also a 2:1 clay mineral, but it has a structure with expandable layers, which allows it to absorb water and expand, making it more than just two layers.

Option (D): This is correct because Montmorillonite is known to swell in contact with water due to the water molecules being absorbed between its layers, which is a characteristic of smectite clays.