The magnetic moment of a diamagnetic atom is

Options

A. Much greater than one
B. 1
C. Between zero and one
D. Equal to zero

Answer

**Solution:**

The magnetic moment of a diamagnetic atom is a fundamental concept in magnetism. Diamagnetic materials are characterized by their weak negative response to an applied magnetic field. This means that when an external magnetic field is applied, diamagnetic materials develop a magnetic moment in the opposite direction to the applied field.

1. **Understanding Magnetic Moment**: The magnetic moment (\( \mu \)) of an atom is typically defined as the product of the current and the area of the loop through which the current flows. In the case of diamagnetic materials, the magnetic moment arises due to the orbital motion of electrons.

2. **Diamagnetic Behavior**: In diamagnetic materials, all the electrons are paired. This means that the magnetic moments due to individual electrons cancel each other out. As a result, the net magnetic moment of a diamagnetic atom is zero in the absence of an external magnetic field.

3. **Induced Magnetic Moment**: When an external magnetic field is applied, the paired electrons experience a slight change in their orbits, which induces a small magnetic moment in the opposite direction to the applied field. However, this induced magnetic moment is still very small compared to the magnetic moments found in paramagnetic or ferromagnetic materials.

4. **Conclusion**: Therefore, the magnetic moment of a diamagnetic atom can be summarized as follows:
- In the absence of an external magnetic field, the magnetic moment is zero.
- Under the influence of an external magnetic field, a small induced magnetic moment is created, but it is still negative and very weak.

Thus, the magnetic moment of a diamagnetic atom is effectively zero in the absence of an external magnetic field.

**Final Answer**: The magnetic moment of a diamagnetic atom is zero.

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