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Define specific surface, diffuse layer

Short answer

Specific surface is total particle surface area per unit mass or volume, increasing as particles get smaller (kaolinite about 15, illite about 80, montmorillonite up to 800 m²/g). Diffuse double layer is the layer of water and cations around a negatively charged clay particle, with cation concentration gradually decreasing with distance from the surface.

Define specific surface and diffuse double layer.

  • Specific surface is the total surface area of the soil particles per unit mass (m²/g) or per unit volume. It rises as particle size falls, e.g. kaolinite about 15 m²/g, illite about 80 m²/g, montmorillonite up to 800 m²/g.
  • Diffuse double layer is the layer of water and positive ions (cations) around a negatively charged clay particle, in which the ion concentration decreases gradually with distance from the particle surface.

✓ Answer checked by Claude Opus 5.5 (high effort)

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