Here's the chemical equation for nitrogen fixation:

N₂ + 8H⁺ + 8e⁻ → 2NH₃ + H₂

Nitrogen fixation is a crucial process for life on Earth as it converts atmospheric nitrogen gas (N₂) into a usable form for organisms. This process is carried out by certain microorganisms, primarily bacteria, and is essential for the production of amino acids, proteins, and nucleic acids.