Freezing activities using liquid nitrogen may be found in several references. Go to Top Go to Teachers Index Possible Extensions 1. Superconductivity is a phenomenon found at low temperatures where certain materials lose all resistance to an electric current. Some students will provide ideas related to levitating trains as related to the Meissner effect. Industrially, nitrogen is produced as a by product in the liquefaction of air to produce pure oxygen.
Air is liquefied by passing it through a series of pressurized cooling systems.
Explain the energy transfers involved in refrigeration. The coolant absorbs heat energy from foods placed in the refrigerator. The cooling process retards bacteria and mold growth, thus increasing the shelf-life of foods. Add hot water to a styrofoam cup of known mass. Determine the total mass and measure the temperature.