Of the 32 known isotopes, Astatine-210, with a half-life of 8.1 hours, is the longest lived. Naturally occurring astatine isotopes have been found in minute amounts in the three natural radioactive decay series, in which they occur by minor branching (astatine-218 in the uranium series, astatine-216 in the thorium series, and astatine-215 and astatine-219 in the actinium series).
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies.
Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style