Question

Which radioactive series show emanation?
A. Neptunium series
B. Uranium series
C. Thorium series
D. Actinium series

Answer 1

Hint: Emanation is the product of radioactive decay. radioactive series are the three naturally occurring radioactive chains and one artificial chain of unstable nuclei that decay alpha and beta until it forms a stable nucleus.

Complete step by step answer:
Emanation is defined as the radioactive gases that are the isotopes of radon and they are also the product of radioactive decay. In radioactive species that show emanation, it forms a product that uses radon with a decay chain. Here, radon is a gas, whereas other heavy elements are not gases. Therefore, radon can escape in the air, whereas other metals cannot. In neptunium series, radon is not formed as a product. Therefore, it does not show emanation as it cannot escape in air, whereas the other series, that is, uranium series, thorium series and actinium series, they form radon as a product, which can escape in air and hence, they can show emanation.

So, the correct options are (B), (C) and (D), that are, uranium series, thorium series and actinium series.

Note: 1.Uranium series is defined as a radium series in which the radioactive series begins with naturally forming Uranium \[-238\]. In this radioactive chain, it consists of highly unstable heavy atomic nuclei, that decays with the sequence of alpha and beta till the time a stable nucleus is achieved.
2.Thorium series is a radioactive series that consists of unstable nuclei. It begins with Thorium $-232$ and ends with lead $-208$ .
3.Actinium series also called as actinium cascade. It begins with naturally forming Uranium \[-235\]. It consists of unstable atomic nuclei which decays through the sequence of alpha and beta till the time it becomes a stable nucleus.
4.Here, the neptunium series, uranium series, actinium series and thorium series, all are radioactive series. These elements are unstable and to make them stable, they release alpha, beta and gamma particles.