Question

The most expansive clay mineral is:

• A. Quartz
• B. Montmorillonite
• C. Kaolinite
• D. Illite

Hint:

Montmorillonite has the highest swelling potential among clay minerals, making it the most expansive.

Answer 1

The Correct Option is B

Step 1: Identifying Expansive Clay Minerals.
Montmorillonite exhibits the greatest expansion among clay minerals. It swells significantly upon water exposure.

Step 2: Answer.
The correct answer is Montmorillonite, corresponding to option (2).

Final Answer:
\[ \boxed{2. \, \text{Montmorillonite}} \]