True or false
protozoans are the only organisms that can convert nitrogen from the air into chemical compounds that plants can use.
if false what is it

The above statement is false.

Explanation:

Protozoans are not the organisms that can convert nitrogen from the air into chemical compounds that plants can use.

Bacteria and archaea are organisms that can convert nitrogen from the air into chemical compounds that plants can use. Organisms which can convert nitrogen to forms that can be used by plants such as ammonia are known as diazotrophs. Examples of such kind of organisms include Rhizobia and azospirillium.

straight fertilizers

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this