>>10970531One of their useful properties is that they are among the heaviest elements having at least some isotopes which are stable, i.e. not radioactive. Everything (every element) north of bismuth (83) is "always radioactive" in the sense that all of the given elements' known isotopes are unstable. Fairly early on in this process are the fairly well-known "hazardous" household names of Radon (86), Radium (88), Uranium (92) and Plutonium (94).
