on disintegration
products of uranium in the Clinton (Oak Ridge) reactor. Marinsky and
Glendenin, who did the chemical work of identification, chose to call it
promethium because they wished to point out that just as Prometheus
stole fire (a great force for good or evil) from the hidden storehouse
of the gods and presented it to man, so their newly assembled reactor
delivered to mankind an even greater force, nuclear energy.

Element 85 is called astatine, from the Greek astatos, meaning
"unstable," because astatine _is_ unstable (of course all other elements
having a nuclear charge number greater than 84 are unstable, too).
Astatine was first made at Berkeley by bombarding bismuth with alpha
particles, which produced astatine and released two neutrons. The
element has since been found in nature as a small constituent of the
natural decay of actinium.

The last of the original 92 elements to be discovered was element 87,
francium. It was identified in 1939 by French scientist Marguerite
Perey.

Children have a game in which they pile blocks up to see how high they
can go before they topple over. In medieval times, petty rulers in their
Italian states vied with one another to see who could build the tallest
tower. Some beautiful results of this game still remain in Florence,
Siena, and other Italian hill cities. Currently, Americans vie in a
similar way with the wheelbase and overall length of their cars. After
1934, the game among scientists took the form of seeing who could extend
the length of the periodic system of the elements; as with medieval
towers, it was Italy that again began with the most enthusiasm and
activity under the leadership of Enrico Fermi.

Merely adding neutrons would not be enough; that would make only a
heavier isotope of the already known heaviest elements, uranium.
However, if the incoming neutron caused some rearrangement within the
nucleus and if it were accompanied by expulsion of electrons, that
_would_ make a new element. Trials by Fermi and his co-workers with
various elements led to unmistakeable evidence of the expulsion of
electrons (beta activity) with at least four different rates of decay
(half-lives). Claims were advanced for the creation of elements 93 and
94 and possibly further (the transuranium elements, Table I). Much
difficulty was experienced, however, in proving that the activity really
was due to the formation of elements 93 and 94. As more people became
interested an