Gaseous nitrogen in the atmosphere has to be converted or "fixed" into a suitable form before it can be utilised by living organisms.
There two main ways of nitrogen fixation are
(a). Biological fixation: Majority (approximately 90%) of nitrogen fixation is carried out by bacteria. Bacterias such as Cyanobacteria transforms nitrogen into ammonium and ammonia : N2 + 3 H2 → 2 NH3. The produced ammonia can then be taken in directly by plants and /or the conversion products of ammonium and ammonia may further react in the process of nitrification.
(b). Fixation by lightning: Lightning energy causes the combination nitrogen (N2) and water (H2O) forming nitrates (NO3) and ammonia (NH3) . Rain water dissolves the formed nitrates and ammonia and the solution is drained into the ground, where they can be reached by plants plant roots for consumption.
Energy exists in different forms, all of which can be classified as either potential energy or kinetic energy. Potential energy is energy stored in an object due to its position or arrangement. Kinetic energy is energy of an object due to its movement - its motion.
