An Overview of Radiation and Radioactivity

Even though Ernest Rutherford was by trade a physicist, a lot of his research served to shed light on once unknown aspects of radioactivity and nuclear chemistry. Of his many contributions to these fields is his classification and description of alpha particles. As will be discussed in subsequent pages, Rutherford didn't necessarily discover alpha particles as much as he recognized their existence. However, a base understanding of the history of radiation and radioactivity must be obtained before Rutherford's contributions are discussed. I shall therefore start from the beginning.

The first steps into deciphering radiation were taken by Wilhelm Röntgen in 1895 when he placed his hand in front of a radioactive source to discover that a shadowed outline of the bones of his hand was being projected onto the screen behind him. Röntgen was so thrilled by this discovery that he isolated himself from everyone he knew (with the exception of brief comments to his wife) so that he could experiment with this unknown form of radiation. Unbeknownst to him at the time, Röntgen was directly exposing himself to high amounts of hazardous radiation; which couldn't had been good for his health. But despite such consequences, Röntgen was able to publish his research soon after the discovery and called the radiation "X-rays."

*Note- For more information on Wilhelm Röntgen's discovery and experimentation with X-rays, click here.

*Note- The image below portrays an early experimental tube that is similar to those that Roentgen and others used to investigate the nature of light.

Röntgen's discovery was worth mentioning because his research catalyzed other scientists into searching for other forms of radiation. One such scientist was Henri Becquerel, who was so intrigued by the Röntgen's discovery that he decided to search for luminescent objects that could produce rays that were similar to X-rays. His early experiments were largely oriented around uranium and its exposure to sunlight (which was done in order to make uranium luminescent). Eventually, (and almost by pure accident), Bacquerel realized that his samples of uranium were radiating regardless as to whether or not they had been stimulated by a light source. The importance of this discovery was that it inspired research into the concept of radioactivity (or radioactive decay) by both the husband and wife pair of Pierre and Marie Curie and our very own Ernest Rutherford.

*Note- Additional information on both Henri Becquerel and Pierre/Marie Curie can be found here.