The permanent magnetic moment of the atoms of a material is not zero. The material

Options

A. must be paramagnetic
B. must be diamagnetic
C. must be ferromagnetic
D. may be paramagnetic

Answer

To solve the question, we need to analyze the properties of different types of magnetic materials based on their magnetic moments.

### Step-by-Step Solution:

1. **Identify the Types of Magnetic Materials**:
- There are three main types of magnetic materials: diamagnetic, paramagnetic, and ferromagnetic.

2. **Understand Diamagnetic Materials**:
- Diamagnetic materials have a magnetic moment (μ) of **0**. This means they do not have a permanent magnetic moment. Since the question states that the permanent magnetic moment is not zero, the material cannot be diamagnetic.

3. **Understand Paramagnetic Materials**:
- Paramagnetic materials have a non-zero magnetic moment. However, this magnetic moment is relatively small compared to ferromagnetic materials. Since the question states that the magnetic moment is not zero, the material could potentially be paramagnetic.

4. **Understand Ferromagnetic Materials**:
- Ferromagnetic materials also have a non-zero magnetic moment, but their magnetic moment is significantly larger than that of paramagnetic materials. The question does not specify whether the magnetic moment is large or small, only that it is not zero.

5. **Evaluate the Options**:
- Given that the magnetic moment is not zero, the material could be either paramagnetic or ferromagnetic. Therefore, we cannot definitively conclude that the material must be one or the other; it could be either.

6. **Select the Correct Answer**:
- The only option that accurately reflects the information given in the question is that the material **may be paramagnetic**. Hence, the correct answer is option 4.

### Final Answer:
The material may be paramagnetic.