Radioactive sources are used to study living organisms, to diagnose and treat diseases, to sterilize medical instruments and food, to produce energy for heat and electric power, and to monitor various steps in all types of industrial processes. Tracers are a common application of radioisotopes.
The term radioactivity was actually coined by Marie Curie, who together with her husband Pierre, began investigating the phenomenon recently discovered by Becquerel. The Curies extracted uranium from ore and to their surprise, found that the leftover ore showed more activity than the pure uranium.
And Marie was proven right: in 1898 the Curies discovered two new radioactive elements: radium (named after the Latin word for ray) and polonium (named after Marie's home country, Poland).
Curie discovered radioactivity, and, together with her husband Pierre, the radioactive elements polonium and radium while working with the mineral pitchblende. She also championed the development of X-rays after Pierre's death.
Soon after his 1896 discovery of radioactivity, Henri Becquerel noticed that the small amount of radium he always carried in his jacket pocket was causing a rash on his skin. Instances such as these prompted a sudden interest in possible medical uses of radioactivity – specifically as a tool to help treat tumours.
Artificially radioactive isotopes can be used in the treatment of disease as well as in its diagnosis. For example, an artificially radioactive isotope of cobalt is used to treat some types of cancer patients. The radiation from the cobalt damages cancerous cells and may prevent the spread of the disease.
The decay of unstable atoms releases radiation, a phenomenon called radioactivity. As unstable atoms exist in all matter, we are surrounded by natural radiation. Radiation can also come from man-made sources, through military, medical or industrial applications. This is commonly referred to as radioactivity.
The discovery of radioactivity changed our ideas about matter and energy and of causality's place in the universe. It led to further discoveries and to advances in instrumentation, medicine, and energy production. It increased opportunities for women in science.
Radioactivity is the property of unstable atomic nuclei to transform spontaneously. The process releases energy (usually by emitting ionizing radiation). In general terms, radiation is the emission of particles or energy.
Uranium was discovered in 1789 by Martin Klaproth, a German chemist, who isolated an oxide of uranium while analyzing pitchblende samples from the Joachimsthal silver mines in the former Kingdom of Bohemia, located in the present day Czech Republic. He named his discovery “uran” after the planet Uranus.
X-rays were first discovered in late 1895 and dangers associated with exposure became apparent very quickly. In 1896 the first injuries due to x-ray exposure were recorded and in 1904 Thomas Edison's assistant Clarence Dally was the first person recorded to have died as a result of x-ray exposure.
Long-lived radioactive elements such as uranium, thorium and potassium and any of their decay products, such as radium and radon are examples of NORM. These elements have always been present in the Earth's crust and atmosphere, and are concentrated in some places, such as uranium orebodies which may be mined.
Neutralizing radioactive materials is not something that can be done in a simple way. The plutonium and uranium parts of nuclear power plant wastes can in principle be used up in some advanced nuclear reactors that might be built in the near future, but this process still produces other radioactive waste materials.
The System International of units (SI system) uses the unit of becquerel (Bq) as its unit of radioactivity. One curie is 37 billion Bq. Since the Bq represents such a small amount, one is likely to see a prefix noting a large multiplier used with the Bq as follows: 37 GBq = 37 billion Bq = 1 curie.
Ernest Rutherford identified the nature of alpha and beta radiations. He connected first alpha radiations to helium and later on identified them to helium nuclei after his discovery of the atom nucleus. He interpreted also the emission of beta particles as the emission of electrons discovered a few years before.
