Question

which of the following forms of nitrogen is shown by number 3 in the image below?

ammonia (nh3)
atmospheric nitrogen (n2)
nitric oxide (no)
nitrite (no2) and nitrate (no3)

Explanation:

In the nitrogen cycle, atmospheric nitrogen (\(N_2\)) is a major component of the atmosphere. The arrows labeled 1 in the image are pointing upwards to the atmosphere. Ammonia (\(NH_3\)) is usually in the soil or water (not in the atmosphere as a major form like \(N_2\)). Nitric oxide (NO) is a reactive gas produced in smaller quantities (e.g., from combustion, not the main atmospheric form). Nitrite (\(NO_2\)) and nitrate (\(NO_3\)) are more commonly found in soil (as forms plants can uptake, related to processes like nitrification, not the main atmospheric form). Since the arrows labeled 1 are in the atmospheric part of the cycle, and \(N_2\) makes up about 78% of the atmosphere, it is the most likely form.

Answer:

Atmospheric Nitrogen (\(N_2\))