Describe the natural method of nitrogen fixation.

Explanation

Natural method of nitrogen fixation: When lightening occurs atmospheric nitrogen and oxyhen combine to form NO The nitric oxide [NO] combines with oxygen to from `NO_(2)`. This nitrogen dioxide combines with rain water to form HNO (Hyponitrous acid) and `HNO_(2)` or `NHO_(2)` and `HNO_(3)`
`N_(2)+O_(2)overset("lightning")(to)2NO`
`2NO+O_(2)to2NO_(2)`
`2NO+H_(2)O to HNO+HNO_(2)`
`2NO+H_(2)O underset("Nitrous acid Nitric acid")(toHNO_(2)+HNO_(3))`
These nitrous acids and nitric acid are washed into the soil along with rain water and cause Acid Rain. This acidic rain water combines with other mineral salts to form nitrities and nitrates. The nitrites and nitrates are absorbed by the plants.