Astatine

Astatine is found in the Earth's crust in uranium ores [3]. The naturally occurring isotopes are ²¹⁵At (T_½ = 10⁻⁴ s), ²¹⁷At (T_½ = 3.26 · 10⁻² s), ²¹⁸At (T_½ = 1.5 s) and ²¹⁹At (T_½ = 56 s) [3].