What is the condition for Rayleigh scattering ?

Explanation

### Step-by-Step Solution:

1. **Understanding Rayleigh Scattering**:
- Rayleigh scattering is a phenomenon that occurs when light interacts with small particles in the atmosphere. It is responsible for the blue color of the sky and other similar effects.

2. **Condition for Rayleigh Scattering**:
- The primary condition for Rayleigh scattering to occur is that the size of the particles causing the scattering must be significantly smaller than the wavelength of the light being scattered.

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