What is the primary component of air?

The primary component of air is nitrogen, which makes up about 78% of the Earth's atmosphere by volume. Nitrogen is an inert gas, meaning it does not easily react with other substances, which is why it constitutes such a large portion of air. This abundance plays a crucial role in various atmospheric processes and helps create a stable environment for life on Earth.

While oxygen is vital for the respiration of many organisms and constitutes around 21% of the atmosphere, nitrogen's dominance is critical in preventing rapid combustion and maintaining a balance with other gases. Carbon dioxide is present in much smaller amounts, essential for photosynthesis and as a greenhouse gas, while hydrogen is found in minuscule quantities and is not a significant component of the air we breathe. Understanding the composition of air is foundational in fields like combustion, atmospheric science, and environmental engineering.