Nitrogen is the seventh element in the periodic table. Nitrogen naturally occurs as a colorless and odorless gas, generally considered to be inert. As a liquid, it is also colorless and odorless, and is similar in appearance to water.
Nitrogen makes up 78% of Earth's atmosphere by volume. The compounds made of nitrogen, combined with other elements, are so active as to be most important in foods, poisons, fertilizers, and explosives.
Nitrogen occurs in many forms and compounds:
- Brizeen nitrate
- Liquid nitrogen
- Nitrogen oxide
- Nitrogen tetroxide
- Nitric acid
- Nitrogenated soil
- Nitrogenase compounds
- Potassium nitrate
- Rhodium nitrite
- Tri-nitrogen chloride
- "The Cage" and "The Menagerie, Part I" – Talos IV had a class M oxygen/nitrogen atmosphere.
- "The Galileo Seven" – Taurus II had a class M oxygen/nitrogen atmosphere.
- "Miri" – Earth Two had a class M oxygen/nitrogen atmosphere exactly identical to Earth, down to continental arrangements and lifeforms.
- "Metamorphosis" – The asteroid in the Gamma Canaris region had a class M oxygen/nitrogen atmosphere, with some krypton, argon, and neon. It was practically identical to Earth.
- "Who Mourns for Adonais?" – Pollux IV had a class M oxygen/nitrogen atmosphere.
- "Bread and Circuses" – 892-IV was nearly identical to Earth, with different shaped landmasses, with a class M oxygen/nitrogen (21%/78%) atmosphere.
- "The Ultimate Computer" – Alpha Carinae II had a class M oxygen/nitrogen atmosphere.
- "Return to Tomorrow" – Arret's sealed chamber had a class M oxygen/nitrogen atmosphere.
- "The Deadly Years" – Gamma Hydra IV had a class M oxygen/nitrogen atmosphere and normal mass.
- "The Empath" – McCoy experienced "the bends" - nitrogen bubbles in his blood.
- "The Savage Curtain" – A select area of Excalbia formed a class M oxygen/nitrogen atmosphere.
- "Spock's Brain" – Sigma Draconis VI's underground installations had a class M oxygen/nitrogen atmosphere.
- "When The Bough Breaks" – An atmospheric N2 drop was not responsible for the Aldeans' sterility.
- "Hollow Pursuits" – The crew is transporting gaseous nitrogen containers, and later use liquid nitrogen in the warp core.
- "The Royale" – Theta VIII's atmosphere is "nasty," according to Geordi La Forge, consisting of liquid neon, methane, and nitrogen.
- "Evolution" – The bridge accidentally floods with nitrogen oxide.
- "Clues" – The Paxans' homeworld had a class M oxygen/nitrogen atmosphere.
- "Timescape" – Picard's temporal narcosis was likened to nitrogen narcosis.
- "The Passenger" - Major Kira Nerys used a fire extinguisher filled with nitrogen to extinguish the fire aboard the Kobliad transport ship Reyab.
- "The Jem'Hadar" – The planet had a class M oxygen/nitrogen atmosphere.
- "Things Past" – Tri-nitrogen chloride is a compound used in plasma grenades.
- "Improbable Cause" – The Yalosians' ambassador required an atmosphere of 60% nitrogen, 10% benzene, and 30% hydrogen fluoride.
- "Parallax" – Kes used nitrogenated soil to start the airponics bay.
- "Phage" – The USS Voyager discovered a planetoid with caverns containing an oxygen-nitrogen atmosphere.
- "Elogium" – Nitrogenated soil.
- "Threshold" – The Doctor set up an environment for Tom Paris containing 80% nitrogen and 20% acidichloride.
- "Basics, Part I" – Nitrogen tetroxide fumes were detected on Teirna's shuttle.
- "Coda" – Janeway and Chakotay were collecting nitrogenase compounds.