Gases Around Us
Part of Chemistry Creations
Every day of our lives we encounter gases – we use them, we breathe them in, we walk through them without noticing.
Today in Chemistry Creations, we are exploring just some of the gases that affect our lives.
Check out this video from Matt to get us started.
As Matt says, oxygen is just one of the gases in the air around us – in fact it’s not even the most abundant. The mixture of gases we call “air” is made up of lots of different kinds. Have a look at the pie chart Earth Atmosphere Composition to learn more.
The gas making up most of the air is called nitrogen, with oxygen being the next most abundant. Small amounts of other gases are also present – including argon (a gas that is pretty much completely unreactive). Also in the mix is carbon dioxide (CO2) – a gas we hear a lot about in the news because of its role in driving climate change. It’s also a very interesting gas in its own right – with lots of uses. We use CO2 to make drinks fizzy – we call them "carbonated". Carbon dioxide is also very useful in its frozen form - below you can see a video of Matt using some frozen carbon dioxide (usually called "dry ice").
You can try making your own lava lamp at home – driven by CO2 – try the instructions in our Make Your Own Lava Lamp (PDF). You’ll be making a lava lamp using oil, water, and fizzy tablets.
It turns out it is not just gases that make up the air around us – there are also things like dust and pollen, as well as smoke or soot or forms of pollution. And of course if the amount of water in the air becomes too great, it falls as liquid water – rain!
The air around us also weighs something! We think of air as being easy to move through (we walk through it without noticing). It’s hard to imagine the air having mass – but at sea level every litre of air weighs just over one gramme. By comparison, one litre of water weighs almost one kilogram (a thousand times as much). Air isn’t very heavy, but there sure is a lot of it! Imagine you’re stood in a square that’s one metre on each side – the column of air above your square weighs 10 tonnes (10,000 kg)!
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