Why nitrogen content of the air you inhale and exhale are the same?

The nitrogen content of the air you inhale and exhale remains largely the same because nitrogen is an inert gas that does not participate in the body's metabolic processes. Inhaled air contains about 78% nitrogen, and when you exhale, the nitrogen is expelled unchanged since it does not get absorbed or utilized by the body. Therefore, the nitrogen concentration remains consistent in both inhaled and exhaled air.