Chemistry of the Stars

Liquid Nitrogen - Colder Than Cold

Chemists can cool Nitrogen gas down low enough to make it a liquid. Liquid Nitrogen is -198 °C - that's nearly 200 degrees colder than ice!

Liquid Nitrogen is so cold that it changes the way things behave. A normal, stretchy piece of rubber becomes brittle and hard when it is held in liquid Nitrogen for just a few seconds. The long, stringy molecules in the rubber are usually free to move around as you stretch them but the liquid Nitrogen freezes them in position. When you try and stretch them they just break and as a result we can smash the rubber off the table!

Organic matter (i.e. Vegetables/fingers) is destroyed by liquid Nitrogen. The water in organic matter is frozen and then expands (water expands when you freeze it - this is actually very unusual!). It bursts through the cell walls and the organic matter is then dead. Where rubber goes back to normal after being frozen in liquid Nitrogen, your fingers would not!


Liquid Nitrogen creates a cloud of water vapour on its surface	A lettuce leaf before it the liquid Nitrogen bath

The lettuce leaf is dipped in liquid Nitrogen	After a few seconds it can be crushed into shards like glass

The remains of the lettuce

Chefs and Chemists working together recently discovered that liquid Nitrogen is excellent for making ice cream! Check out the video of this along with all our other videos here.

Next - Our Celebrity for Nitrogen

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The Universe is Expanding - The Big Bang - Fusion - We Were Made in the Stars! - Stars? - Most Common Elements - Iron is in you! - Iron is in Ink! - Our Star for Iron - Oxygen - It Keeps You Alive! - More Oxygen for a Better Flame - Our Celebrity for Oxygen - Nitrogen - Seemingly boring but not... - Liquid Nitrogen - Colder Than Cold - Our Celebrity for Nitrogen - Carbon is Amazing! - Carbon Dioxide - Our Celebrity For Carbon - Hydrogen - Small but Perfectly Formed - Explosive Hydrogen - Our Celebrity for Hydrogen - The End of the Universe

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