Final answer:
In the nitrogen cycle, atoms that appear "lost" are actually transformed and recycled throughout the ecosystem, consistent with the law of conservation of matter. They change form or move between molecules in processes like nitrogen fixation and decomposition, but do not disappear.
Step-by-step explanation:
When atoms seem to be "lost" during the transformations in the nitrogen cycle, what is actually happening is not a loss but a transformation. The law of conservation of matter maintains that matter cannot be created or destroyed. In biological cycles such as the nitrogen cycle, this means that even if we cannot immediately see where certain atoms are, they are still somewhere in the ecosystem. They may have moved from one type of molecule to another or have changed form through various processes like nitrogen fixation, decay, nitrification, and denitrification.
During nitrogen fixation, atmospheric nitrogen (N₂) is converted into forms usable by plants, such as ammonium (NH₄⁺) or nitrate (NO₃⁺). Should these atoms seem "lost," they might have been taken up by plants, or assimilated by microorganisms in the soil. Similarly, during decomposition, the nitrogen in organic matter is converted back to ammonium, nitrate, or even nitrogen gas, thereby continuing the cycle.
It's essential to note that the nitrogen cycle is a complex system with many interchangeable forms of nitrogen that exist between the atmosphere, the lithosphere (earth's solid surface), and the biosphere (living organisms). Therefore, when atoms are not found in an expected place in the environment, they have likely transitioned into a different stage of the cycle or have been temporarily stored in another medium, such as in biomass or soil organic matter.