Question

Which isotope of carbon is radioactive?

Answer 1

Hint: The carbon is a nonmetal present in the fourteenth group in the p block of the modern periodic table. The isotopes are two or more atoms with the same atomic number but different mass numbers due to the different number of neutrons present in those atoms. The carbon atom has fifteen known isotopes.

Complete answer:
Till now, the fifteen isotopes of carbon are known, $ ^8C{ - ^{22}}C $ out of which $ ^{12}C{\& ^{13}}C $ are stable.
Commonly, carbon isotopes come in three variants. By a wide margin, the most well-known isotope of carbon will be carbon-12 $ {(^{12}}C) $ , which contains six neutrons against its six protons. The following heaviest carbon isotope, carbon-13 $ {(^{13}}C) $ , has seven neutrons. Both $ ^{12}C{\& ^{13}}C $ are called stable isotopes since they don't rot into different structures or components over the long haul. The uncommon carbon-14 $ {(^{14}}C) $ isotope contains eight neutrons in its core. In contrast to $ ^{12}C{\& ^{13}}C $ , this isotope is unsteady, or radioactive. After some time, a $ {(^{14}}C) $ particle will rot into a steady item or we can say decay into the stable form of the product.
The longest-lived radioisotope is $ {(^{14}}C) $ , with a half-life of $ 5,730years $ . This is also the only carbon radioisotope found in nature—trace quantities are formed in cosmic space by the reaction $ ^{14}N + {\;^1}n \to {\;^{14}}C + {\;^1}H $ .
The most stable artificial radioisotope is $ {(^{11}}C) $ , which has a half-life of $ 20.364minutes $ .
Hence, the radioactive isotope of carbon is $ {(^{14}}C) $ .

Note:
 $ {(^{14}}C) $ is created by thermal neutrons from enormous radiation in the upper environment, and is shipped sensibly to be consumed by living organic material. Isotopically, $ {(^{14}}C) $ comprises an insignificant part; yet, since it is radioactive with a half-existence of $ 5,730years $ , it is radiometrically discernible. Since dead tissue doesn't assimilate $ {(^{14}}C) $ , the measure of $ {(^{14}}C) $ is one of the techniques utilized inside the area of paleontology for radiometric dating of natural material.