# Inner electrons 125 # Outer electrons 85 # Protons 210 An-Isotope 85:210 Approval Stats BE - Actual 1640.45 BE - Nucleon 7811.66 Decay EC+B+ 99.825, A 0.175 Element Astatine Half Life 8.1 h Mass Actual 209.99 Mass Calculated 211.64 Mass H Norm 208.36 Stability Unstable