see <a href="https://en.wikipedia.org/wiki/Nitrogen_inversion" class="extiw" title="w:Nitrogen inversion">Nitrogen inversion</a>
<a href="//commons.wikimedia.org/wiki/User:Incnis_Mrsi" title="User:Incnis Mrsi">Incnis Mrsi</a>
2012-08-19
<span class="int-own-work" lang="en">Own work</span>