👉 The term "protoactinium" is often used to denote a radioactive nuclide that has not yet reached its stable isotopic abundance. In this context, "proto" refers to a phase of matter that is still in the process of becoming stable, while "actinium" refers to an element with a relatively high atomic number and a relatively low mass. The term is often used to denote the initial stage of a nuclear reaction or the early stages of radioactive decay.
