Nitrogen
| Nitrogen is a chemical element with symbol N and atomic number 7. It is colorless and odorless gas, one of the most common elements in the universe, that makes up 78% of the atmosphere of breathable air. The alchemists knew nitric and hydrochloric (hydrogen and chlorine) acid as aqua fortis ('royal water'), a mixture that could dissolve gold. Works attributed to Jabir (Geber, possible origin of word gibberish) like Summa Perfectiones about aqua regia and aqua fortis circulated in Europe. It was discovered in 1772 by Daniel Rutherford (Royal Society of Edinburgh) and Henry Cavendish (Cecil bloc). Antoine Lavoisier called it azote (no life). Saltpeter was used in gunpowder and as fertilizer. Nitrous oxide is known as laughing gas. Phosphorus is part of the nitrogen family. It is used to put out and control fire (ignite). |  |
Liquid nitrogen is used to cool down superconductors and in the snack Dragon's Breath.
Fritz Haber developed the Haber process to produce ammonia.