What is the major component of Earth's atmosphere?

The major component of Earth's atmosphere is nitrogen, which constitutes about 78% of the atmosphere by volume. This colorless, odorless gas plays a crucial role in maintaining the stability of the atmosphere and in various biological processes. Nitrogen doesn't support combustion, which is vital for life as it helps maintain a balanced environment where living organisms can thrive.

While oxygen is essential for respiration in many life forms and comprises about 21% of the atmosphere, it is not as abundant as nitrogen. Carbon dioxide is present in trace amounts, around 0.04%, and plays a critical role in photosynthesis and as a greenhouse gas, but it is also far less prevalent than nitrogen. Argon, another inert gas, makes up about 0.93% of the atmosphere. Therefore, among these components, nitrogen is by far the most significant in terms of volume and plays a vital role in Earth's atmosphere and ecosystems.