The research conducted by scientist Marie Curie initially focused on her thesis about Natural Radioactivity, which was discovered by Henri Becquerel in 1896.
Starting in 1898, she aimed to accurately determine the characteristics of this radiation by measuring the maximum intensity (which was very weak) of the ionizing current that could be emitted in the air as a result of it.
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Marie Curie with her scientific work on Uranium ore (Image: perso.orange.fr) |
She later used an electrometer (a device to measure electric charge) that Pierre had calibrated, which was perfectly suited for her research. She conducted various analytical experiments to determine whether Uranium ore was the only source of radiation. She discovered that compounds of Thorium emitted the same type of rays.
Uranium ore (Pitchblende) exhibited radioactivity four times greater than expected. Marie concluded that the strong radioactivity of Uranium ore was due to the presence of elements called Radioactive substances, which have the property of transforming into other substances while releasing energy within the ore, but in very small amounts, making them difficult to detect by classical chemical analysis.
At that time, Pierre collaborated with Marie. They immersed themselves in the laborious and meticulous work of isolating chemical substances. During that period, research was not funded as it is today, but the young couple managed to secure a poorly isolated storage area while facing unusual weather conditions with rain and snow. They worked with a helper named André Debierne. Using the electrometer, they measured the radioactivity in the fractions produced from their chemical separations.
In July 1898, they discovered the first element they named Polonium, in honor of Marie’s homeland.
The analysis of Barium obtained during the processing of uranium ore allowed them to demonstrate the presence of a second radioactive element in very small amounts, which they called Radium, and they published their discovery in 1898, emphasizing that the radioactivity of this substance was very high.
She also compiled a table listing all known radioactive elements by 1910. Common points were placed in the same row.
KNOWN RADIOACTIVE ELEMENTS IN 1910
| Thorium. | Uranium | |
| Actinium | Mesothorium 1 | Radio-Uranium |
| Mesothorium 2 | Uranium X | |
| Radioactinium | Radio-Thorium | Ionium |
| Actinium X | Thorium X | Radium |
| Radium A | ||
| Actinium A | Thorium A | Radium B |
| Actinium B1 | Thorium B | Radium C |
| Actinium B2 | Thorium B | Radium C |
| Radium D | ||
| Actinium C | Thorium D | Radium E |
| Radium F (Polonium) |
Impact on Society
The discovery of radioactive substances provided many means for researching the structure of atoms and atomic nuclei. Marie Curie identified applications for radioactive materials in Chemistry, medicine, and especially in Biology. The Curie treatment, which Pierre perfected before their wedding, was combined with surgery and X-ray technology to combat cancer.
Marie asserted that if Radium were in the hands of a murderer, it would be extremely dangerous. She established over 200 X-ray rooms during World War I, helping more than one million injured soldiers.
Today, radioactive materials and X-rays are used in Medicine, Archaeology, Geology, art restoration, and food preservation. In the near future, we hope to see beneficial new applications emerge, provided that scientists align their work with ethical considerations.
