Nitrogen Cycle

Nitrogen is a gas . It makes up 71%
of the gases in the atmosphere!
It helps us by keeping living things
 alive so we can eat them ! Here
is how nitrogen dose it. It is called
the nitrogen cycle . First the
nitrogen falls with rain or snow.
Then goes into the dirt and mud.
Bacteria that are on plants make
 this nitrogen edible for the plants.
The nitrogen is turned into compounds.
Then the the plants use it. Animals eat it .
When the animals die the nitrogen goes
 back to the earth . Where it turns into
food for the Plants. Some nitrogen compounds
don't get used because another bacteria takes
them and makes them plain nitrogen. This
nitrogen Then goes back into the atmosphere
to fall down in rain or snow again. This cycle
keeps animals and plants alive so we can eat
them . That is the nitrogen cycle.








Source: Brainpop