Rate of diffusion is directly proportional to.........

Explanation

To solve the question "Rate of diffusion is directly proportional to...", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Diffusion**:
- Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration. In gases, this means the molecules move throughout the available space.

**Hint**: Remember that diffusion involves the movement of particles from high to low concentration.
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