Radium then undergoes a cascade of alpha decays that leap over astatine.

Funnily enough, astatine is at the same time far more robust than francium.

Past polonium (skipping over, for now, the ultra-rare element astatine) sits radon.

At the same time, francium shuttles atoms away from astatine, causing astatine to remain rare.

This makes francium (and astatine, for similar reasons) highly unstable.

If astatine is so rare, it's natural to ask how scientists ever took a census of it.

There just isn't much astatine out there.

Still, it's more abundant than astatine.

If you had a million atoms of the longest-lived type of astatine, half of them would disintegrate in four hundred minutes.

For instance, at least twenty to thirty ounces of astatine's near neighbor on the periodic table, francium, exist at any moment.

And in that six million billion billion kilos, the total amount of astatine, the scarcest natural element, is one stupid ounce.

No one will likely ever produce a visible sample of astatine either, but at least it's good for something-asa quick-actingradioisotope in medicine.

In fact, after scientists-ledby our old friend Emilio Segrè-identifiedastatine in 1939, they injected a sample into a guinea pig to study it.

Halogen-free power cords' environment-friendly credentials -they are free of elements derived from fluorine, chlorine, bromine, iodine and astatine -ensure they earn higher margins.

Astatine remains the only element whose discovery was confirmed by a nonprimate.

Astatine, for instance, is practically unstudied.