Alveolar air has more/less oxygen than atmospheric air.

Explanation

**Step-by-Step Solution:**

1. **Understanding Alveoli**: Alveoli are tiny air sacs in the lungs where gas exchange occurs. They are crucial for the respiratory process, allowing oxygen to enter the blood and carbon dioxide to be removed.

2. **Composition of Atmospheric Air**: Atmospheric air is composed of approximately 21% oxygen, 78% nitrogen, and small amounts of other gases, including carbon dioxide.

3. **Gas Exchange Process**: During respiration, oxygen from the alveolar air diffuses into the blood, while carbon dioxide from the blood diffuses into the alveolar air. This exchange is essential for maintaining the oxygen supply in the body and removing carbon dioxide.

...