DISCOVERY OF RADIOACTIVITY
this section, you will be able to do the following:
radioactive elements and fluorescent minerals.
what role radioactive elements and fluorescent minerals play
in the discovery of radioactivity.
How was radioactivity
The discovery of radioactivity, in
general, actually came about on a few different fronts. First
was the discovery of X-ray radiation that was artificially generated
in a laboratory, followed by the discovery of several elements
that naturally emit radiation when the nucleus of the atoms disintegrate
or decay. These are the elements that today are called radioactive
elements and are said to have unstable nuclei.
Just before the turn of the century,
in the mid to late 1890's, several scientists were working with
cathode ray tubes investigating properties of fluorescent minerals.
Fluorescent minerals are certain minerals that glow when
exposed to sunlight. At the same time, other scientists were busy
gathering evidence on the theory that the atom could be divided
into even smaller subatomic particles. Some of this new evidence
showed that certain types of atoms disintegrate by themselves.
In the following three sub-units you
will learn about the discovery of X-ray, the discovery of radioactive
elements, and you will find out who the Curies were and what contribution
to science they made.
- When the
nucleus of an element decays or disintegrates radiation is emitted,
and this kind of element is called a radioactive element.
that glow when sunlight is exposed on them are called fluorescent