Substance in which the magnetic moment of a single atom is not zero, is know as

Options

A. diamagnetism
B. ferromagnitism
C. Paramagnetism is magnetic independent
D. ferrimagneitsm

Answer

To solve the question, "Substance in which the magnetic moment of a single atom is not zero, is known as," we will analyze the options provided and determine which one correctly describes the substance with a non-zero magnetic moment.

### Step-by-Step Solution:

1. **Understanding Magnetic Moments**:
- A magnetic moment is a vector quantity that represents the magnetic strength and orientation of a magnet or current loop. In atoms, it arises from the motion of electrons and their intrinsic spin.

2. **Analyzing the Options**:
- **Option A: Diamagnetism**: Diamagnetic materials have all their electrons paired, resulting in a net magnetic moment of zero. Therefore, this option is incorrect.
- **Option B: Paramagnetism**: Paramagnetic materials have unpaired electrons, which means that the magnetic moments of these unpaired electrons do not cancel out. Thus, they have a net magnetic moment that is not zero. This option is a strong candidate.
- **Option C: Paramagnetism is magnetic independent**: This statement is misleading. While paramagnetic materials do exhibit a magnetic moment, the phrase "magnetic independent" does not accurately describe the nature of paramagnetism. Therefore, this option is incorrect.
- **Option D: Ferrimagnetism**: Ferrimagnetic materials also have unpaired electrons, leading to a net magnetic moment. However, this term is more specific to materials where the magnetic moments of different ions or atoms are unequal and opposite, resulting in a net moment. While this option could be correct in certain contexts, it is not the most straightforward answer to the question.

3. **Conclusion**:
- The best answer to the question is **Option B: Paramagnetism**, as it directly refers to substances where the magnetic moment of a single atom is not zero due to the presence of unpaired electrons.

### Final Answer:
**Paramagnetism**