Question

Nitrogen in the atmosphere must be “fixed” before it can be used by plants. Atmospheric nitrogen is “fixed” by

Answer 1

D) bacteria and lightning.

Step-by-step explanation:

According to USA Testprep (Where the question came from), "Nitrogen is fixed or chemically combined with other elements to form a usable chemical compound. Plants are then able to use nitrogen in this form; they are not able to use it in its atmospheric form." I hope this helps those that try to find the answer.

Answer 2

Atmospheric Fixation. The enormous energy of lightning breaks nitrogen molecules and enables their atoms to combine with oxygen in the air forming nitrogen oxides. These dissolve in rain, forming nitrates, that are carried to the earth.