1, liquid nitrogen smoke is actually not "smoke", but "water vapor". The temperature of liquid nitrogen is-196 degrees. At room temperature, liquid nitrogen comes into contact with air, which contains water, and water molecules condense to form water vapor, which is the scene of "smoking".

2. Liquid nitrogen is inert, colorless, odorless, non-corrosive, non-flammable and extremely low in temperature. Nitrogen accounts for 78.03% of the atmospheric volume and 75.5% of the atmospheric weight. Nitrogen is inert and does not support combustion, but it is not an essential element to sustain life.