Compare plasma emission with fluorescence by indicating what is common and what is different for the two light emitting mechanisms.

Plasma is a state of matter, generated when a gas of ions and atoms, have some of their orbital electrons and free electrons removed. Artificially, plasma can be generated by heating an electrically neutral gas, or subjecting the gas to a strong electromagnetic field until the gas becomes increasingly electrically conductive. This excited atoms and ions then emit electromagnetic radiation usually within the visible range, at wavelengths characteristic of the particular gas used, and are confined by a strong magnetic field.

On the other hand, fluorescence occurs when an excited molecule, atom, or subatomic particles like electrons relaxes to a lower energy state (possibly the ground state) by emitting energy in the form of a photon. It may have been directly excited from the ground state by absorbing energy in the form of a photon, subsequently emitting a photon of lower energy as it relaxes back to its initial lower state.

The common characteristics between these two phenomenon is that they both lead to the emission of energy in the form of photons, which is the unit of an electromagnetic energy or wave.

The difference is that plasma emission can only occur at a very high temperature, whereas fluorescence can occur at a wide range of temperatures between high and low temperatures.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.