The invisible gas that makes up most of the planet's atmosphere is nitrogen. Comprising approximately 78% of the Earth's atmosphere, nitrogen is an inert gas that plays a fundamental role in various biological and physical processes. While it is not directly used by humans and most animals for respiration, nitrogen is essential for life as it is a critical component of amino acids, proteins, and nucleic acids. It is also involved in forming the framework of the Earth's ecosystems. This abundance of nitrogen helps maintain atmospheric stability and affects weather patterns as well.