In 1911, Rutherford conducted a series of experiments in which he bombardeda piece of gold foil with positively charged (alpha) particles emittedby radioactive material. Most of the particles passed through the foilundisturbed, suggesting that the foil was made up mostly of empty spacerather than of a sheet of solid atoms. Some alpha particles, however, "bouncedback," indicating the presence of solid matter. Atomic particles, Rutherford'swork showed, consisted primarily of empty space surrounding a well-definedcentral core called a nucleus. In a long and distinguished career, Rutherford laid the groundwork forthe determination of atomic structure. In addition to defining the planetarymodel of the atom, he showed that radioactive elements undergo a processof decay over time. And, in experiments which involved what newspapersof his day called "splitting the atom," Rutherford was the first to artificiallytransmute one element into another--unleashing the incredible power ofthe atom which would eventually be harnessed for both beneficial and destructivepurposes. Taken together, the work of Becquerel, the Curies, Rutherford and others,made modern medical and scientific research more than a dream. They madeit a reality with many applications. A look at the use of isotopes revealsjust some of the ways in which the pioneering work of these scientistshas been utilized.
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