INFORMATION:
We need to select which ion is not part of the nitrogen cycle
STEP BY STEP EXPLANATION:
To identify the ion that is not a part of the nitrogen cycle, let see the nitrogen cycle:
Nitrogen is the most abundant element in our planet’s atmosphere
1. Fixation: Nitrogen in its gaseous form (N2) can’t be used by most living things. It has to be converted or ‘fixed’ to a more usable form through a process called fixation. Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants.
2. Decomposition: Plants take up nitrogen compounds through their roots. Animals obtain these compounds when they eat the plants. When plants and animals die or when animals excrete wastes, the nitrogen compounds in the organic matter re-enter the soil where they are broken down by microorganisms, known as decomposers. This decomposition produces ammonia, which can then go through the nitrification process.
3. Nitrification: Nitrifying bacteria in the soil convert ammonia into nitrite (NO2-) and then into nitrate (NO3-). This process is called nitrification. Compounds such as nitrate, nitrite, ammonia and ammonium can be taken up from soils by plants and then used in the formation of plant and animal proteins.
4. Denitrification: Denitrification completes the nitrogen cycle by converting nitrate (NO3-) back to gaseous nitrogen (N2). Denitrifying bacteria are the agents of this process. These bacteria use nitrate instead of oxygen when obtaining energy, releasing nitrogen gas to the atmosphere.
We can see that in the nitrogen cycle NH4+, NO2 and NO3 take part. So, the ion that is not a part of the nitrogen cycle is NO+.
ANSWER:
NO+