The ability to produce and control nuclear reactions is affecting, and
will doubtless continue to affect, human life in two outstanding ways.
One way is by making tremendous amounts of energy available, either as
explosions or as energy released from controlled reactions for peacetime
use. The other way is by producing a vast variety of radioactive
isotopes, first in the particle accelerators (“atom smashers”) mentioned
earlier, and now in large quantities in nuclear reactors.
The presence of a radioactive isotope can be detected by instruments
like the familiar Geiger counter; for this reason isotopes make
wonderful tracers. These telltale atoms, which, in effect, continually
cry “Here I am,” can trace the course of a chemical element through any
kind of chemical reaction. Chemists are taking advantage of this new way
of tagging atoms to study reaction patterns that, heretofore, have been
obscure.
As a consequence, a scientist’s ability to synthesize scarce chemicals
is being increased. The exact role of numerous essential trace elements
in the growth and metabolism of living things, including people, is
being studied by the use of tagged atoms.