Page "Nitrogen" Paragraph 13

At atmospheric pressure molecular nitrogen condenses ( liquefies ) at 77 K (− 195. 79 ° C ) and freezes at 63 K (− 210. 01 ° C ) into the beta hexagonal close-packed crystal allotropic form.

Below 35. 4 K (− 237. 6 ° C ) nitrogen assumes the cubic crystal allotropic form ( called the alpha-phase ).

Liquid nitrogen, a fluid resembling water in appearance, but with 80. 8 % of the density ( the density of liquid nitrogen at its boiling point is 0. 808 g / mL ), is a common cryogen.