Which colorless gaseous element occupies about 4/5 of the air?

The colorless gaseous element that occupies about 4/5 of the air is nitrogen. In the Earth's atmosphere, nitrogen is the most abundant gas, making up approximately 78% of the total volume of air. This large proportion plays a critical role in various ecological and physiological processes.

Nitrogen is essential for living organisms as it is a key component of amino acids, proteins, and nucleic acids, which are all vital for life. Additionally, nitrogen does not readily react with other elements under standard conditions, which means it acts as an inert filler in the atmosphere that can help dilute oxygen and other reactive gases.

Understanding this fundamental aspect of atmospheric composition is crucial for fields such as environmental science, biology, and chemistry, highlighting the significance of nitrogen beyond just its presence in the air.