The predominant gas in Earth's atmosphere is nitrogen, which comprises about 78% of the atmosphere by volume. The atmosphere is a complex mixture of gases, and nitrogen is followed by oxygen, which makes up approximately 21%. Other components, including argon, carbon dioxide, and trace gases, account for the remaining percentage. Nitrogen is crucial for various biological processes, and it serves as an inert gas that helps regulate the atmosphere's composition. Its abundance allows it to act as a buffer in ecological and climatic systems, supporting life on Earth while playing a role in weather patterns.