nitrogen has definitions from the field of chemistry
[ noun ] (chemistry) a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues


atomic_number_7 N

Used in print

(James A. Ibers et al., "Proton magnetic resonance...)

For the low-temperature measurements the sample was cooled by a cold nitrogen gas flow method similar to that of Andrew and Eades .