Helium is used for more than balloons

Kids might know that balloons are bad for wildlife. Indeed, when filled with helium, a balloon can travel several kilometers in the sky before losing its ability to float. When it falls back to Earth, the string, rubber, or Mylar becomes a hazard to birds, turtles, and many other creatures that can become entangled or choked on what they mistake for a tasty treat.

But many people don’t realize there’s another reason to cling to these balloons: the helium they contain is a scarce resource.

“I think one of the coolest things is that helium is the second most abundant element in the entire universe, but ironically on planet Earth we only have very, very small amounts of it. “, said Santiago Toledo, a chemist at the American University. in Washington, D.C.

This is true for several reasons. For example, helium atoms do not like to bond with other elements or even with themselves. As a result, they have a very low density — much lower than the density of the particles that make up air, Toledo said.

So when you force a bunch of helium into an enclosed space, like a balloon, that low density allows the helium to rise above the heavier air around it. This is why helium balloons float.

This is also why the Earth has so little, he said. Most of the planet’s helium is locked up underground, usually as a mixture with natural gas, Toledo said. But whenever helium is exposed to the air, it vanishes into space.

That’s kind of bad news, because helium has many uses beyond birthday party decorations. While most of us know it as a gas, helium becomes liquid at extremely cold temperatures.

“We’re talking about temperatures that are roughly what’s called ‘absolute zero,’ which is the coldest temperature that could possibly be in the universe,” Toledo said. Because of this quirk, scientists use liquid helium to keep many types of instruments cold.

If you’ve ever had to have a medical test called an MRI, or magnetic resonance imaging, the helium was there to cool the superconducting magnets that run the machines. Additionally, helium is important for creating digital devices such as smartphones, as well as the fiber optic cables that give us the internet. Helium is also necessary for the proper functioning of NASA rockets and is an important part of machines called magnetometers, which help the US military detect enemy submarines.

The good news, Toledo said, is that the balloons don’t just contain helium, but rather a mixture of light gases. Yet when he sees one peeking out into the sky, all he can think about is how a precious resource floats up and away.

Comments are closed.