Question

How is \[Carbon - 14\]produced in the upper atmosphere?

Answer 1

Hint: Carbon is a non-metallic element which is present in group \[14\]of the periodic table. It forms various compounds and it forms more compounds than all other elements combined. \[Carbon - 14\] is a radioactive isotope of carbon and is often used in the process of radiocarbon dating and radiolabelling.

Complete step-by-step answer:
\[Carbon - 14\] is called radiocarbon and is a byproduct of cosmic ray collisions. With the aid of a variety of reactions, \[Carbon - 14\] is produced in the atmosphere and the most important reaction is between thermalized neutrons from cosmic radiation and nitrogen atoms.

These cosmic rays are emitted by stars, supernovas, black holes etc. This process occurs in the upper atmosphere. These collisions are similar to that which take place in particle accelerator labs. There is an emission of high energy neutrons in this process.

There are nitrogen atoms present in the air and when the neutrons emitted collide with the nitrogen atoms, a proton is emitted and this results in the formation of radiocarbon.

The reaction for the following will be:
\[n{ + ^{14}}N{ \to ^{14}}C + p\]

\[Carbon - 14\] has a half life of \[\tau \approx 5000yrs\]and that’s the reason behind radiocarbon dating being used to approximate the age of a fossil. It can also be formed by reaction in nuclear tests.


Note: when \[Carbon - 14\] is produced, it reacts similar to that of stable \[Carbon - 12\] and it further bonds with oxygen and creates \[C{O_2}\] molecules and then it is further processed in the food chain via the process of photosynthesis. The same ratio of \[Carbon - 14\] to \[Carbon - 12\] is constantly being cycled through the animal or plant as long as they live.