Why is `CO_(2)` gas transferred from alevoli to atmospheric air ?

Explanation

### Step-by-Step Solution:

1. **Understanding Gas Exchange**: The transfer of gases in the lungs occurs through a process called diffusion, which is driven by differences in partial pressures of the gases involved.

2. **Partial Pressure Concept**: Each gas in a mixture exerts its own pressure, known as partial pressure. The movement of gases occurs from areas of higher partial pressure to areas of lower partial pressure.

3. **Partial Pressure of CO₂ in Alveoli**: In the alveoli, the partial pressure of carbon dioxide (CO₂) is approximately 40 mm Hg.

...