Goal 2 – There’s gas in the air?

Mixture of Gases in Air All Other Gases Argon = 0.93% Carbon Dioxide = 0.04%

NITROGEN A major part of proteins, including DNA Dilutes (thins out) the oxygen – too much or too little oxygen and we would die! Turned into useful form by nitrogen-fixing bacteria

OXYGEN Necessary to survive! Our cells use oxygen to create energy All of the oxygen in our atmosphere has been created by plants – photosynthesis! Burning requires oxygen

CARBON DIOXIDE Used by plants for photosynthesis A greenhouse gas – carbon dioxide helps keep our planet warm Increases in CO2 have been making the planet warmer: global warming!

TRACE GASES OZONE helps filter out the sun’s harmful rays ARGON is used in light bulbs because it will not catch fire even in extreme heat WATER VAPOR can condense to form clouds HELIUM inflates balloons and blimps