Which of the following essential element is not properly placed in the given category?

Options

A. Cu
B. Zn
C. Mg
D. Mn

Answer

To solve the question regarding which essential element is not properly placed in the given category, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Essential Elements**: Recognize that essential elements are nutrients required for the growth and development of plants. There are 17 essential elements, which can be categorized into non-mineral and mineral elements.

2. **Identify Non-Mineral Elements**: The three non-mineral essential elements are carbon (C), hydrogen (H), and oxygen (O). These are not part of the options given in the question.

3. **List Mineral Essential Elements**: The mineral essential elements include nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), boron (B), chlorine (Cl), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), and nickel (Ni).

4. **Categorize Macronutrients and Micronutrients**:
- **Macronutrients**: These are required in larger amounts and include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
- **Micronutrients**: These are required in smaller amounts and include elements like iron, manganese, zinc, copper, and others.

5. **Examine the Options**: The options provided are:
- Copper (Cu)
- Zinc (Zn)
- Magnesium (Mg)
- Manganese (Mn)

6. **Classify Each Element**:
- Copper (Cu) - Micronutrient
- Zinc (Zn) - Micronutrient
- Magnesium (Mg) - Macronutrient
- Manganese (Mn) - Micronutrient

7. **Identify the Misplaced Element**: From the classification, we see that magnesium is the only element listed as a macronutrient, while the others (copper, zinc, and manganese) are micronutrients. Therefore, magnesium is not properly placed in the category of micronutrients.

### Conclusion:
The essential element that is not properly placed in the given category is **Magnesium (Mg)**.

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