The Secret World of Gases
Liquid oxygen. Credit: Public domain

The Secret World of Gases

19/07/2018Written by Tori Tasker

The curious (and sometimes explosive) science behind our summer 2018 family activities.

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mascot Telescope Right
Secret World of Gases. Credit: National Space Centre

Everywhere we look there are millions of gas particles, moving around as the air we breathe and the atmosphere we live in. These invisible particles are a mix of nitrogen, carbon dioxide, argon, neon, helium, hydrogen, oxygen, and methane.

This ‘Secret World of Gases’ has inspired our summer 2018 holiday programme at the National Space Centre.

From the combustion of oxygen to the hydrogen that could power a house, the gases of our planet help us conduct interactive experiments and an explosive family talk, with a special spotlight on hydrogen, nitrogen, oxygen, and carbon dioxide.

Powerful Hydrogen

Powerful Hydrogen
Space Shuttle launch. Credit: NASA

Imagine if the only product to come out the exhaust pipe of your car was water? This car is a possible car of the future. In this same future is a house running on the same power source: hydrogen gas.

When combined with oxygen from our atmosphere, hydrogen gas can power houses and vehicles without producing pollutants. Currently there are three hydrogen fuel cell powered cars on the market, but before you buy come and visit us at the National Space Centre this summer to test drive our very own mini London bus. You can also see a three story doll’s house in action, powered entirely by hydrogen

This hydrogen gas is stored in a device called a ‘Hydrostik’. This small stick can store 10 litres of hydrogen gas in the form of a metal hydride. The Hydrostik funnels the hydrogen gas towards a fuel cell. This is what enables our house or bus to have power. The hydrogen gas and oxygen from the surrounding air are pulled together in the fuel cell. In this process, the electrons from the hydrogen are separated from the protons and are run through an external circuit. This produces electricity and a by-product of water!

Icy Nitrogen

Nitrogen is the most common gas in our atmosphere. It makes up around 78 percent of our atmosphere. On our planet nitrogen is a colourless and odourless gas, however, on other planets with different surface temperatures, this is not necessarily the case. On Pluto, there are solid nitrogen plains next to water ice mountains.

Nitrogen takes the form of a solid, liquid, or gas at different temperatures than water. At -195oC nitrogen is a liquid and able to condense air around it. This means we can shrink an inflated balloon.

By blowing up a balloon and lowering it into a container of liquid nitrogen we can see the balloon shrink. This is because the air inside the balloon is being lowered to the temperature of the liquid nitrogen and is changing from a gas to a liquid. If the balloon is taken out of the liquid nitrogen the temperature of the room will force the liquid air to change back into a gas, and the balloon will re-inflate!

Explosive Oxygen

Explosive Oxygen
Liquid oxygen. Credit: Public domain

Similar to nitrogen, oxygen will change between a liquid, gas, or a solid at different temperatures than water. Oxygen makes up around 21 percent of the air we breathe and is the third most common element in the universe.

Oxygen is essential to the process of combustion, which is essentially just the name for burning something. Combustion is especially important for transportation, especially for rockets headed into space. Rockets are partly fuelled by liquid oxygen.

As a liquid, oxygen makes something much more flammable. Oxygen from the air will make a piece of tissue burn quickly. However, if this piece of tissue is soaked in liquid oxygen, the combustion reaction will occur almost instantaneously!

Credit: National Space Centre

The Secret World of Gases is running from Saturday 14 July until Sunday 2 September 2018.

Join us between 11:00 and 16:00 daily in our Science Zone for live experiments and talks! To find out more and to book tickets, click here.

The Secret World of Gases is funded by the UK Association for Science and Discovery Centres and supported by the Royal Society of Chemistry and BOC.

About the author: Tori Tasker is the Public Programmes Team Leader at the National Space Centre.