Question

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

Explanation:

To solve this, we analyze each option:

• "thrown away in a landfill..." is incorrect as nitrogen isn't just in landfills.
• "in the nonliving portion of the environment" is correct. The nitrogen cycle includes non - living components like the atmosphere (where most nitrogen is as \(N_2\)), soil, water, etc., when not in living organisms.
• "stored deep in Earth's core" is wrong as nitrogen isn't mainly stored there.
• "not in existence..." is wrong because matter (like nitrogen atoms) is conserved and exists in other parts of the environment.

Answer:

B. in the nonliving portion of the environment (assuming the options are labeled A, B, C, D with B being "in the nonliving portion of the environment")