The Radioactive Elements Radium And Polonium Were Found By Marie And Pierre Curie
The Curie’s work on radiation led to the possibility of cancer treatment, but also provided a better understanding of the atom. That is that an atom has a nucleus at its centre with surrounding energy shells which consist of negatively charged electrons.
The electron was discovered in 1897 by J.J. Tomson, and was the first proved element of the atom. The nucleus is made up of the proton, a positively charged particle, and the neutron, a particle with no charge. The proton’s existence was confirmed by Rutherford while the neutron was discovered by physicist, Sir James Chadwick.
Knowledge of the atomic structure helped in identifying isotopes. An isotope is an element with an unstable amount of neutrons and protons, these occur in nature and emit radiation. A radioisotope however, is created when a stable element is bombarded with alpha particles, thereby destabilising the element and making it radioactive. Radioisotopes are what make up the radioactive material used in treatment of cancers.
It was Rutherford who found that radiation could be classified into two categories. Alpha for those easily absorbed and Beta for its greater penetration ability. But in 1990, it was Paul Villard that discovered a third more penetrating radiation, called Gamma.
These particles, alpha, beta and gamma, are emitted from an atom when an element…