Isotopes of astatine
Nuclides with atomic number of 85 but with different mass numbers / From Wikipedia, the free encyclopedia
Astatine (85At) has 41 known isotopes, all of which are radioactive; their mass numbers range from 188 to 229 (though 189At is undiscovered).[2] There are also 24 known metastable excited states. The longest-lived isotope is 210At, which has a half-life of 8.1 hours; the longest-lived isotope existing in naturally occurring decay chains is 219At with a half-life of 56 seconds.