What's in the Air?

A green, blue and grey exhibit.
A green, blue and grey exhibit.

Air is not mainly composed of oxygen.

How it works

Place puzzle pieces representing proportions of gases within the pie chart.

Things to try or ask around the exhibit

What is the most common gas in Earth's atmosphere?


Only 21% of Earth's atmosphere is composed of oxgyen. The vast bulk of Earth's air is composed of nitrogen gas (78%), There aretraces of other gases such as argon, helium, etc., but combined they only make up 1% of Earth's air.

Nitrogen is a stable gas, which means it doesn't do much and won't harm lung tissue when we breathe it in and out. Although other gases are found in tiny amounts as trace gases, they are important. Some protect Earth from subzero temperatures in space (carbon dioxide and methane), while others protect Earth from ultraviolet radiation (ozone gas) and changing weather patterns (water vapour).

Finding the science in your world

While carbon dioxide is usually around 0.04% of Earth's atmosphere, it (together with methane) have strong physical effects on Earth, so if they increase too much in concentration, the balance of keeping Earth's temperature steady is threatened, generating effects of climate change.

Helium gas is famous for its use in balloons, but it's actually quite rare and supplies of helium are running low around the world. Other rare gases are used a great deal in industry or medicine, such as argon gas, which is used in medical lasers.