The complete oxidation of the nitrogen gas takes place in 3 steps:

Step1: Lighting provides the high activation energy needed for the oxidation of the unreactive nitrogen gas to forms nitrogen(II) oxide Step2:Nitrogen(IV) oxide dissolves in water droplets in the air, and react with more oxygen, to form a dilute solution of nitric acid. The dilute acid falls to the Earth in rain. Step 3: The sequece of reactions in the atmosphere forms part of the natural nitrogen cycle. In this way, nitrogen from unreactive, insoluble nitrogen gas can get into the soil in a soluble form that plants can absorb