All you need to know about the gas that makes balloons float
Whether you’re a curious adult or a kid who’s researching a science project, read our facts about helium to find out more about the mysterious gas.
Where does it come from?
The element is made either by the nuclear fusion process of the Sun, or by the very slow and steady radioactive decay of rock, which is how all of Earth’s helium was made. There is no way of manufacturing it. It is often found underground along with natural gas. The Earth’s biggest reserves are in North America.
After being extracted, the helium and natural gas mix is cooled. During this process, the natural gas turns into a liquid while the helium stays in gas form and can be separated and stored.
More science facts about helium:
- It doesn’t turn to a liquid until it reaches -270°C! Its boiling and melting points are the lowest of the elements, so it only exists as a gas except under very extreme conditions
- It’s symbol is He and atomic number is 2, so each atom of helium has two protons
- It is colourless, odourless, tasteless, non-toxic, and inert
- It is the second-lightest element – hydrogen is the lightest element
- It is the second-most abundant element in the universe, though it is scarce on Earth
Who discovered it?
It was first discovered by Pierre Janssen, a French astronomer in 1868. While observing a solar eclipse in India, he noticed the yellow spectral emission lines of the element. English astronomer Norman Lockyer later named it helium after the Greek name helios – sun.
It is in only 1895 that Sir William Ramsay discovered the gas on earth.
People will often inhale the contents of a balloon to make their voice sound squeaky, yet there’s an inherent risk of asphyxiation or suffocation, which may lead to serious injury or death.
While such accidents are very rare, they are a tragic reminder that helium should NEVER be inhaled.
When using disposable helium canisters, make sure you read all the safety instructions carefully.
What we use helium for:
Initially hydrogen was used to make party balloons float. However, it can explode and is highly flammable and was was used mainly for scientific experiments. Hydrogen was eventually replaced by helium and found it’s way out of the science lab to the toy market!
When latex balloons are filled with helium they typically float only for a day or so. The gas escapes through small pores in the latex. You can treat latex balloons with a hi-float gel that makes them less porous and helps lock the gas in.
Foil and plastic balloons are less permeable and can float for anything from 5 days to 5 weeks depending on their size and the material used for manufacture.
The gas can also be used to lift airships and blimps.
Because of its low boiling point, helium is used to cool the superconducting magnets in medical MRI scanners.
Science / industry
Helium is widely used in science experiments, but also to:
- Maintain the low temperature of the Large Hadron Collider in Cern
- Clean out rocket engines. Large quantities of helium are used to pressurise the interior of liquid fuel rockets, condense hydrogen and oxygen to make rocket fuel, and force fuel into the engines during rocket launches
- Estimate the age of rocks and minerals containing uranium and thorium by measuring their retention of helium
- Prevent the heating of the air in solar telescopes, which reduces the distorting effects of temperature variations in the space between lenses
- Cool infra-red detectors, nuclear reactors and the machinery of wind tunnels
To avoid the problems caused by breathing ordinary air under high pressure, deep sea divers use a mixture of helium, oxygen and nitrogen to breathe underwater.
Helium is also a non-renewable resource and scientist are now warning that the world’s reserves of the precious gas are about to run out, a shortage that is likely to have far-reaching repercussions.
The American reserves in Kansas – the largest on the planet, are being depleted at an unprecedented rate. The low cost of the gas is not encouraging recycling of the large quantities used in industry.
Why the world is running out of helium
A US law means supplies of the gas – a vital component of MRI scanners – are vanishing fast.