Answer 1:
Astatine (Greek for "unstable") is a very rare
radioactive element that occurs during the
radioactive decay of uranium. As it's name
suggests, astatine is not a very stable atom,
quickly radioactively decaying into other, smaller
atoms. Astatine was only discovered in 1940, and
only about 30 grams (about a teaspoon worth) of it
are thought to exist on the entire earth at any
one time; and the half-life of the most stable
form of Astatine is about 8 hours. However,
scientists have performed experiments on the very
tiny amounts of astatine they can produce by
bombarding bismuth with high-energy alpha
particles. These short-lived observations tell us
that Astatine reacts similarly to Iodine, another
Halogen. Lithium will form a compound with
Iodine, Lithium iodide, so it is likely that
lithium and astatine would similarly combine--
but such a molecule would last only minutes or
hours before breaking apart, and current methods
could produce only micrograms of the molecule at a
time. If the ability to make astatine became more
routine, it might be useful in applications like
radiation therapy for cancer -iodine localizes
to certain parts of the body, and astatine might
as well. If those areas have cancer, the
radioactivity from the astatine could damage the
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