Nuclear Transformations 431
Marie Sklodowska Curie(1867–
1934) was born in Poland, at that
time under Russia’s oppressive
domination. Following high school,
she worked as a governess until she
was twenty-four so that she could
study science in Paris, where she
had barely enough money to
survive. In 1894 Marie married
Pierre Curie, eight years older and
already a noted physicist. In 1897,
just after the birth of her daughter
Irene (who was towin a Nobel
Prize in physics herself in 1935), Marie began to investigate
the newly discovered phenomenon of radioactivity—her
word—for her doctoral thesis.
The year before, Becquerel had found that uranium emitted
a mysterious radiation. Marie, after a search of all the known
elements, learned that thorium did so as well. She then
examined various minerals for radioactivity. Her studies
showed that the uranium ore pitchblende was far more
radioactive than its uranium content would suggest. Marie and
Pierre together went on to identify first polonium, named forher native Poland, and then radium as the sources of the
additional activity. With the primitive facilities that were all
they could afford (they had to use their own money), they had
succeeded by 1902 in purifying a tenth of a gram of radium
from several tons of ore, a task that involved immense physical
as well as intellectual labor.
Together with Becquerel, the Curies shared the 1903 Nobel
Prize in physics. Pierre ended his acceptance speech with these
words: “One may also imagine that in criminal hands radium
might become very dangerous, and here one may ask if hu-
manity has anything to gain by learning the secrets of nature,
if it is ready to profit from them, or if this knowledge is not
harmful.... I am among those who think... that humanity
will obtain more good than evil from the new discoveries.”
In 1906 Pierre was struck and killed by a horse-drawn car-
riage in a Paris street. Marie continued work on radioactivity,
still in an inadequate laboratory, and won the Nobel Prize in
chemistry in 1911. Not until her scientific career was near an
end did she have proper research facilities. Even before Pierre’s
death, both Curies had suffered from ill health because of their
exposure to radiation, and much of Marie’s later life was marred
by radiation-induced ailments, including the leukemia from
which she died.80 84 88 92130N
=A- Z
Zα decay
β decay140(^234) Th
(^206) Pb
(^210) Po
(^210) Pb
(^210) Ti^214 Po
(^214) Pb
(^218) Po
(^222) Rn
(^226) Ra
(^230) Th
(^234) U
(^234) Pa
(^234) Th
(^238) U
(^214) Bi
(^210) Bi
Figure 12.7The uranium decay series (A 4 n2). The decay of^21483 Bi may proceed either by alpha
emission and then beta emission or in the reverse order.
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