Which of the following terms is not related to colloids?

Options

A. Brownian movement
B. Dialysis
C. Ultrafiltration
D. Wavelength

Answer

To determine which term is not related to colloids, we will analyze each of the provided options: Brownian movement, dialysis, ultrafiltration, and wavelength.

### Step-by-Step Solution:

1. **Understanding Brownian Movement**:
- Brownian movement refers to the random zigzag motion of colloidal particles when observed under a microscope. This phenomenon is a characteristic property of colloids and indicates the presence of particles suspended in a medium.
- **Conclusion**: Brownian movement is related to colloids.

2. **Understanding Dialysis**:
- Dialysis is a process used to purify colloidal solutions. It involves the use of a semi-permeable membrane that allows smaller impurities to pass through while retaining the larger colloidal particles. This process is specifically relevant to colloids because it addresses the separation of colloidal particles from smaller solutes.
- **Conclusion**: Dialysis is related to colloids.

3. **Understanding Ultrafiltration**:
- Ultrafiltration is similar to dialysis but uses filter paper with fixed pore sizes to separate colloidal particles from smaller impurities. This method is also applicable to colloidal systems, as it helps in the purification of colloidal solutions.
- **Conclusion**: Ultrafiltration is related to colloids.

4. **Understanding Wavelength**:
- Wavelength refers to the distance between successive crests of a wave and is a property associated with wave phenomena. While all particles have a wavelength associated with their wave nature (as per de Broglie's hypothesis), this concept is more relevant at the quantum level (for very small particles like electrons) rather than at the macroscopic level where colloidal particles exist.
- **Conclusion**: Wavelength is not specifically related to colloids in a practical sense.

### Final Answer:
The term that is not related to colloids is **wavelength**.

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