If a solid is finely divided:

Options

A. Its adsorption ability increases
B. Its adsorption ability decreases
C. Its surface area decreases
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Finely Divided Solids:**
- A solid that is finely divided means that it has been broken down into smaller particles or powder form. This increases the total surface area of the solid.

2. **Surface Area and Adsorption:**
- The adsorption ability of a solid is directly related to its surface area. The larger the surface area, the more area is available for molecules to adhere to the surface.

3. **Example of a Block:**
- Consider a wooden block with a surface area represented as \(6a\) (where \(a\) is the area of one face). When this block is cut in half, it creates two new surfaces, effectively increasing the total surface area.

4. **Effect of Cutting the Solid:**
- Each time the solid is cut, new surfaces are created. For instance, cutting the block into smaller pieces increases the total surface area available for adsorption.

5. **Conclusion:**
- As the solid is divided into finer particles, the surface area increases significantly, leading to an increase in its adsorption ability. Therefore, the correct answer to the question is that the adsorption ability increases.

**Final Answer:**
- If a solid is finely divided, its adsorption ability increases.

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