Liquid nitrogen is just very cold nitrogen. It is 320oF below zero (-196oC). It's so cold that it freezes anything it touches almost instantly. Also, anything at normal room temperature is so much hotter than liquid nitrogen that the liquid nitrogen boils when it touches something.
Why does liquid nitrogen not freeze?
Now, liquid nitrogen boils and evaporates at room temperature, but that process is too slow to cool it enough to freeze. ... As the liquid nitrogen boils away faster and faster, it cools down the remaining liquid nitrogen until it eventually reaches the freezing point of -346. This solid nitrogen can't stay, however.
How cold can liquid nitrogen get?
Liquid nitrogen (LN) is an inert cryogenic fluid with a temperature of − 196 °C [− 320 °F].
