Nitrogen

About Nitrogen

Nitrogen runs the table on oxidation states — every integer from -3 to +5 shows up in stable compounds, from ammonia to nitrate. The reason it's chemically interesting is the same reason it's biologically inaccessible: the N≡N triple bond holds 945 kJ/mol, the second-strongest bond between any two atoms, which is why 78% of the atmosphere just sits there refusing to react. Cracking that bond is what Haber and Bosch figured out in 1909 with a promoted iron catalyst at 400 °C and 200 atm — arguably the most consequential industrial reaction ever run, since the ammonia it produces feeds roughly half the world's nitrogen-fertilizer chain and, by extension, about half of everyone alive. In the lab N₂ is the cheap inert blanket gas; liquid N₂ at 77 K is the workhorse cryogen for everything from cold traps to NMR magnet refills. The compounds span an enormous range of behavior — NH₃ is a base, HNO₃ is a strong oxidizing acid, NO is a signaling molecule in mammals, and TNT and RDX are what happens when you keep adding nitro groups.