By Charles Gibson, MiSci Outreach and Innovation Director
As part of my job at the Michigan Science Center, I take exciting science demonstrations and programs out on the road. The Traveling Science team brings the science center experience to communities around the state – 54 counties and growing. We’re on track to hit all 83 counties soon.
One of my favorite demonstrations to share with audiences uses liquid nitrogen, a chemical element that’s currently popular online as part of the Dragon’s Breath Challenge. While it looks cool, eating food soaked in liquid nitrogen and blowing the gas from your nose and mouth can be dangerous!
First, what is liquid nitrogen? We normally come into contact with nitrogen as a gas. In fact, most of the air around us is filled with it – 78 percent of the air on earth is nitrogen. The rest of the air is made up of the oxygen that we breathe and the carbon dioxide that helps plants. Nitrogen is normally a gas, so how do we get liquid nitrogen?
As we bring the temperature down, the nitrogen gas turns into liquid nitrogen through a process called condensation. Condensation happens when matter changes its physical state and goes from a gas phase to a liquid phase.
For nitrogen, the temperature must be under -320° Fahrenheit to be in the liquid state. I don’t have to tell you that this is really, really, really cold. Temperatures this low can be dangerous and can cause cold burns or asphyxiation (suffocation).
At the Science Center, and on the road, our educators use cryogenic gloves for protection. These gloves protect our hands and arms when working in ultra-cold environments. We are also trained professionals who know how to handle liquid nitrogen safely.
Here are a few more fun facts about nitrogen (both liquid and gas):
- At normal pressure, liquid nitrogen boils at -195.8°C or -320.4°F
- Liquid nitrogen freezes at -210°C or -346°F
- Nitrogen can be converted to a solid by placing it in a vacuum chamber pumped by a rotary vacuum pump
In addition to educational purposes, liquid nitrogen can also be used for freezing and transporting food products; preservation of biological samples; coolant for superconductors, vacuum pumps, and other materials and equipment; removing skin abnormalities; and cooling materials for easier machining or fracturing.
If you or child is interested in liquid nitrogen or the Dragon’s Breath challenge, I encourage you to learn more at the Michigan Science Center – in a safe and fun environment, under the guidance of trained educators. I hope to see you at the Science Center (or in the community) soon!