Gases

Air is a mixture of gases that we cannot see.

Air is a mixture of several gases.

Air is a mixture of gases.

Air is a mixture of various gases.

Liquids are heavier than gases.

These gases can lead to global warming.

Exhaust gases of a car are noxious.

If we burn fuels such as coal, oil and gas, they give off various gases.

Heat will break this chemical down into harmless gases.

Sometimes because of their atmospheres and sometimes because of the gases which surround them.