Question

what is the source of carbon-14 in our environment?
the reaction of atomic o with neutrons in the upper atmosphere.
the beta-decay of b.
the reaction of atomic n with neutrons in the upper atmosphere.
the alpha-decay of o-18.

Explanation:

Carbon - 14 is formed in the upper atmosphere when atomic nitrogen (N) reacts with neutrons. Cosmic rays produce neutrons in the upper atmosphere, and these neutrons interact with nitrogen - 14 ($^{14}\text{N}$) atoms. The reaction is $^{14}\text{N}+n
ightarrow^{14}\text{C}+p$ (where $n$ is a neutron and $p$ is a proton). The other options are incorrect: reacting atomic O with neutrons does not produce C - 14, beta - decay of B does not form C - 14, and alpha - decay of O - 18 also does not produce C - 14.

Answer:

The reaction of atomic N with neutrons in the upper atmosphere.