Like solids and liquids, gas is a common state of matter.
Pure gases are made up of just one atom. Neon is an example of a pure gas.
Elemental gases are made up of two or more of the same atoms joined together. Hydrogen gas (H2) is an example an elemental gas.
Compound gases contain a combination of different atoms. Carbon monoxide (CO) is an example of a compound gas.
The air we breathe here on Earth is made up of different gases. It contains around 78% nitrogen, 21% oxygen, 1% argon and a small amount of other gases.
Natural gas contains mostly methane, it is used as a fuel to generate electricity and is common in the home where it can be used for heating, cooking and other purposes.
Gas pressure is measured in pascals.
The helium balloons you get at parties and carnivals float because helium is lighter than the air surrounding it.
Noble gases are a group of chemical elements that are very stable under normal conditions. Naturally occurring noble gases include helium, neon, argon, krypton, xenon and radon.
The ozone layer that protects Earth from the Sun’s potentially damaging UV light is made up of ozone (O3), an oxygen allotrope containing 3 oxygen atoms bound together.
Nitrous oxide (N20) is a gas with interesting properties that allow it to be used in a variety of different ways, these include as an anesthetic in hospitals (you may have heard it referred to as laughing gas) and to increase the power of engines in motor racing (often called nitrous or just NOS).