Question

which form of matter is most relevant to the nitrogen cycle you
a h₂o
b co₂
c n₂
d po₄

question 3 (1 point)
which form of matter is most relevant to the phosphorus cycle you
a po₄
b co₂
c h₂o
d n₂

Explanation:

The nitrogen - cycle involves the transformation of nitrogen - containing compounds. Nitrogen gas ($N_2$) is the most abundant form of nitrogen in the atmosphere and is central to the nitrogen - cycle processes like nitrogen fixation. For the phosphorus - cycle, phosphate ($PO_4$) is the key form as phosphorus is mainly found in the form of phosphate in rocks, soil, and water, and it moves through the ecosystem in the form of phosphate.

Answer:

For the nitrogen - cycle question: C. $N_2$
For the phosphorus - cycle question: A. $PO_4$