How does a radioactive decay chain form?

A radioactive decay chain forms when an unstable, radioactive nucleus undergoes a sequence of successive decays, producing a series of "daughter" nuclei that are often themselves radioactive. This process continues through consecutive alpha decay and beta decay steps until a stable, non-radioactive nucleus is finally achieved.12

Because each decay event changes the identity of the atom—by altering the number of protons and neutrons—a collection of identical parent atoms will, over time, transform into a mixture of various different elements as they progress through the chain.1

Key characteristics of these chains include:
* Genetic Relationship: Members of a series are genetically related, as each daughter nucleus is the direct product of the preceding parent's decay.2
* Branching: In some cases, a specific nucleus may decay in more than one way, leading to different possible paths within the chain.2
* Natural and Artificial Series: There are four primary decay series, three of which occur naturally (the thorium, uranium, and actinium series) and one that is produced artificially (neptunium).2