Astatine

chemistry · radioactive · super rare

Impossibly rare element. Astatine is the rarest naturally occurring element in Earth's crust. It only exists as a decay product when heavier elements break down over time.

All isotopes unstable. Every form of astatine is radioactive and falls apart quickly. The longest-lasting one, astatine-210, only lasts about 8 hours before transforming into something else.

Heat from its own decay. Astatine is so radioactive that any solid chunk of it would immediately vaporize from the heat of its own radioactivity, which is why scientists have never actually seen a solid sample.

Element 85 on the periodic table. Astatine has the atomic symbol At and sits at position 85 on the periodic table, between iodine and francium.