Why is the presence of clay particles important in soil? a. They provide macronutrients—particularly nitrogen, phosphorus, and potassium. b. They bind metal ions, which would be toxic if absorbed by plants. c.They allow water to percolate through the soil, making oxygen-rich air pockets available. d. The negative charges on clay bind to positively charged ions and prevent them from being leached out of the soil.

Verified step by step guidance

1. Step 1: Understand the question. The question is asking why clay particles are important in soil. It provides four possible answers, each suggesting a different role that clay particles might play.
2. Step 2: Consider each answer in turn. Answer a suggests that clay particles provide macronutrients. While it's true that soil needs to contain certain nutrients for plants to grow, these are generally provided by organic matter and minerals in the soil, not by clay particles.
3. Step 3: Look at answer b. This answer suggests that clay particles bind metal ions, which could be toxic to plants. This is partially correct. Clay particles can bind to certain ions, but this is not their primary role in soil.
4. Step 4: Consider answer c. This answer suggests that clay particles allow water to percolate through the soil, creating oxygen-rich air pockets. While clay particles can help with water retention, they do not typically create air pockets.
5. Step 5: Finally, consider answer d. This answer suggests that the negative charges on clay particles bind to positively charged ions, preventing them from being leached out of the soil. This is the most accurate answer. Clay particles do have a negative charge, which allows them to bind to positively charged ions (cations) in the soil. This prevents these nutrients from being washed away by water, making them available for plant roots to absorb.