Question

When a radioactive isotope decays into a nucleus which is also unstable and undergoes decay, and this process is repeated several times, the succession of reactions is called a________.

a. fission reaction.
b. decay series.
c. half-life.
d. fusion reaction.
e. none of these

Answer 1

Decay series

Step-by-step explanation:

A succession of radioactive decay is termed decay series. The radios decay of an unstable nuclei usually continues until a stable isotope is reached. This continuous decay of radioactive isotopes is also known as a radioactive cascade.

It is important to note that most radioisotopes do not decay directly to form a stable nuclei. Instead, they undergo a series of decay until a stable isotope is formed. An example of a decay series can be seen in the decay of uranium-238 to uranium-234.

U-238 is more radioactive than U-234. U-238 first undergoes an alpha particle decay to form thorium 234. This is known as the daughter nuclei. Afterwards, thorium 234 undergoes decay to give protactinium 234. This then undergoes a beta negative decay to form the uranium 234 nuclei.