What percentage of the atmospheric composition is nitrogen?

The correct response is based on the fact that nitrogen constitutes approximately 78% of Earth's atmosphere by volume. This percentage reflects the significant role nitrogen plays in maintaining the balance of gases that are vital for life. It is relatively inert and does not easily react with other elements, which helps to stabilize the atmosphere and provides a buffer for the more reactive gases.

Understanding the composition of atmospheric gases is essential in fields such as firefighting and other environmental science areas, as it impacts fire behavior and the behavior of gases in different conditions. The other percentages listed do not accurately represent nitrogen's proportion in the atmosphere, as 21% is the approximate percentage of oxygen, while 1% and 25% do not correlate with known atmospheric gas concentrations.