As products of radioactive decay, astatine and the like are too scarce and ephemeral to tally directly but their abundances can be inferred from their parent elements’ well-known half-lives and decay profiles. Precious metals are heavy. Just below is a chart comparing the original eight. ...
they slowly transform into other isotopes of the same element through gaining or losing neutrons, and eventually they become other elements entirely. This depends on their decay rate, which is known as a half-life. Uses of radioisotopes often depend on their half...