Q:

What did Henri Becquerel contribute to atomic theory?

A:

In 1896, French scientist Antoine Henri Becquerel discovered radioactivity which was an early contribution to atomic theory. He discovered this phenomenon while experimenting with uranium and a photographic plate.

Know More

Full Answer

Becquerel began his experiment by exposing a crystal that contained uranium to sunlight. After the crystal had soaked up some sunshine, Antoine Becquerel placed it on a photographic plate. The uranium crystal imprinted its image on to the photographic plate, leading Becquerel to the conclusion that the uranium was releasing the absorbed energy of the sun in the form of an x-ray. In the absence of light, however, the uranium still imprinted its image on to the photographic plate. Becquerel was surprised, since there was no obvious source of energy involved. He assumed the image was caused by a spontaneous emission from the uranium, but he had in fact discovered radioactivity.

Following up on Becquerel's discovery, Pierre and Marie Curie began experimenting with uranium and the concept of radioactivity. In 1903, the Curies and Becquerel were jointly awarded the Nobel Prize in physics for the discovery of radioactivity and their research. Marie Curie also discovered two new radioactive elements which were named polonium and radium. She was awarded a second Nobel Prize in 1911 for her findings, become the first person to ever be awarded two Nobel Prizes.

Learn more in Chemistry

Related Questions

  • Q:

    How did Einstein contribute to atomic theory?

    A:

    In 1905, Albert Einstein published an analysis in which he devised a mathematical way to predict the size of both atoms and molecules. At the time, the science of atoms was still in its infancy, but Einstein's test was crucial in leading the way towards testing the reality of atoms.

    Full Answer >
    Filed Under:
  • Q:

    When was Mendeleev's contribution to the atomic theory published?

    A:

    Dmitri Mendeleev published his periodic table of elements in 1869. His table arranged the known elements according to their chemical properties and in order of their relative atomic mass. This created several gaps in the periodic table and allowed him to predict eight other undiscovered elements correctly.

    Full Answer >
    Filed Under:
  • Q:

    What is Bohr's atomic theory?

    A:

    Bohr's atomic theory suggests that atoms have a positively charged nucleus that is orbited by electrons that move in circles. These electrons move in specific, distinct orbital levels. This theory has since been made obsolete but has had a lasting impact on the understanding of atomic structure and quantum physics.

    Full Answer >
    Filed Under:
  • Q:

    What contribution is Henri Becquerel noted for?

    A:

    Antoine Henri Becquerel was a French physicist who, while using newly discovered X-ray technology to study the effects of light on uranium salts, discovered a new type of radiation. This new form of radiation coming from the uranium salts registered on a photographic plate.

    Full Answer >
    Filed Under:

Explore