Why does the percentage of Nitrogen in the atmosphere stay approximately stable?
Because Nitrogen is basically stable and does not readily combine without energy. Plants “fix” nitrogen into the soil, and other processes release it again, but nitrogen itself deeds “help” to combine. not like oxygen or hydrogen which readily find partners and need little stimulus to combine. Some Nitrous compounds are created during lightning strikes, the same as OZONE ( O3 ) which does not occur naturally because of the energy required to combine it.
