Question

if an atom of nitrogen is not in a living organism,
where is it?
stored deep beneath the earths surface in its core
in the nonliving portion of the environment
not in existence anywhere else in the universe
thrown away in a landfill on the surface of the earth

Explanation:

Nitrogen atoms cycle between living organisms and the nonliving environment. They can be in the atmosphere (as \(N_2\)), soil (in compounds like nitrates), water (as dissolved nitrogen compounds), etc. The Earth's core has very high temperatures and pressures and is not a typical storage place for nitrogen atoms in a form relevant to this context. Nitrogen atoms do exist outside living organisms in the non - living environment. Also, nitrogen is one of the most abundant elements in the universe (not just in living organisms on Earth), so the option "not in existence anywhere else in the universe" is incorrect. And nitrogen atoms are not typically "thrown away in a landfill" in a way that is relevant to their natural cycling; landfills are more about waste disposal of complex organic and inorganic materials, not a major reservoir for nitrogen atoms in a non - living context compared to the atmosphere, soil, etc.

Answer:

B. in the nonliving portion of the environment