The maximum size of particle of clay is
- A0.2 mm
- B0.02 mm
- C0.002 mmCorrect
- D0.0002 mm
Solution
Concept
Maximum particle size threshold for clay
Formula
NONE
Step-by-step solution
1. Soil particles are classified into gravel, sand, silt, and clay based on particle size according to standard soil classification systems. 2. Silt particles range in size from 0.002 mm to 0.075 mm. 3. Clay particles are defined as particles having an equivalent diameter smaller than 0.002 mm. Answer: C
Explanation
According to standard soil classification systems, clay minerals consist of extremely fine soil particles with a diameter smaller than 0.002 mm. Particles larger than 0.002 mm up to 0.075 mm are classified as silt, while those above 0.075 mm are classified as sand. Therefore, 0.002 mm serves as the upper size limit for clay particles.
Why the other options are wrong
A) 0.2 mm falls in the fine to medium sand size range. B) 0.02 mm represents the upper size boundary for silt particles. D) 0.0002 mm is well below the standard 0.002 mm boundary for clay classification.
Shortcut
Maximum particle size for clay is 0.002 mm (2 microns).
Common mistake
Confusing the maximum particle size of clay (0.002 mm) with the upper size limit of silt particles.
Correct answer: C) 0.002 mm