Which french chemist noticed that uranium salts

Becquerel took this as evidence that his idea was correct, that the phosphorescent uranium salts absorbed sunlight and emitted a penetrating radiation similar to x-rays.

He reported this result at the French Academy of Science meeting on February 24, Seeking further confirmation of what he had found, he planned to continue his experiments. But the weather in Paris did not cooperate; it became overcast for the next several days in late February.

On March 1, he opened the drawer and developed the plates, expecting to see only a very weak image. Instead, the image was amazingly clear. The next day, March 2, Becquerel reported at the Academy of Sciences that the uranium salts emitted radiation without any stimulation from sunlight. Possibly he was motivated by simple scientific curiosity.

Or maybe he was simply impatient. Whatever his reason for developing the plates, Becquerel realized he had observed something significant. He did further tests to confirm that sunlight was indeed unnecessary, that the uranium salts emitted the radiation on their own. At first he thought the effect was due to particularly long-lasting phosphorescence, but he soon discovered that non-phosphorescent uranium compounds exhibited the same effect.

In May he announced that the element uranium was indeed what was emitting the radiation. Becquerel initially believed his rays were similar to x-rays, but his further experiments showed that unlike x-rays, which are neutral, his rays could be deflected by electric or magnetic fields.

Many in the scientific community were still absorbed in following up on the recent discovery of x-rays, but in Marie and Pierre Curie in Paris began to study the strange uranium rays. They figured out how to measure the intensity of the radioactivity, and soon found other radioactive elements: polonium, thorium and radium. Soon Ernest Rutherford separated the new rays into alpha, beta and gamma radiation, and in Rutherford and Frederick Soddy explained radioactivity as a spontaneous transmutation of elements.

Becquerel and the Curies shared the Nobel Prize for their work on radioactivity. Somewhat less well known is the fact that forty years earlier, someone else had made the same accidental discovery. Abel Niepce de Saint Victor, a photographer, was experimenting with various chemicals, including uranium compounds.

Like Becquerel would later do, he exposed them to sunlight and placed them, along with pieces of photographic paper, in a dark drawer. Upon opening the drawer, he found that some of the chemicals, including uranium, exposed the photographic paper. Niepce thought he had found some new sort of invisible radiation, and reported his findings to the French Academy of Science. Awarded the Nobel Prize in Chemistry for her discovery of two new elements, Curie remains the only person to win Nobel Prizes in both physics and chemistry.

Marie suffered from radiation-induced lesions and died of leukemia, likely caused by radiation. She was active in research almost until her death in The following year, her daughter and son-in-law, Irene and Frederic Joliot-Curie, were awarded the Nobel Prize in Chemistry for their discovery of artificially induced radiation. Boundless vets and curates high-quality, openly licensed content from around the Internet.

This particular resource used the following sources:. Skip to main content. Nuclear Chemistry. Search for:. Discovery of Radioactivity. Learning Objective Discuss the history of the discovery of radiation. Key Points The emission of the rays Becquerel discovered is called nuclear radioactivity, and the rays themselves are called nuclear radiation. A nucleus that spontaneously destroys part of its mass to emit radiation is undergoing radioactive decay.

Radiation does not vary with chemical state. Marie and Pierre Curie discovered two new radioactive elements, which Marie named polonium and radium. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet. September 17,