Contributions to the Atomic Theory

By Crawdaddy

  • Joseph Priestly

    Best known for his discovery that plants released oxygen via photosynthesis. He called this dephlogisticated air. He also noted that it supported combustion. Friends with Ben Franklin and Thomas Jefferson. Born- March 24, 1733. Died- February 6, 1804.

  • John Dalton

    Dalton proposed the theory that all matter was made up of atoms. He also stated that it was indestructible and the building blocks of life as we know it. This was crucial for other scientists to build off of this theory. He worked with his student James Prescott Joule. Born- September 6, 1776. Died- July 27, 1844.

  • Avogadro

    Avogadro concluded that there are 6.022*10^23 elementary entities in one mole. It is used to calculate one mole of a substance. This was the first finding of what was actually in a mole. He worked with Joseph Louis-Gay Lussac and John Dalton. Born- August 9, 1776. Died- July 9, 1856.

  • Dimitri Mendeleev

    Mendeleev organized the elements into a table according to their atomic weights. The elements were arranged by ascending order The table was used to organize and predict new elements. He worked with Robert Bunsen on most of his ideas. Born- February 8, 1834. Died- February 2, 1907.

  • JJ Thomson

    Thomson was the first to discover the electron. He created the plum pudding model so the electron could be placed in it. He is credited with the discovery of the first atomic particle. He worked with John Strutt and Edward John Routh. Born- December 18, 1856. Died- August 30, 1940.

  • Albert Einstein

    Probably the most famous physicist who is best known for his theory of E=MC^2. This made the atomic bomb less of an idea and more of an inevitable sequence. He is also famous for his theory of relativity, but this does not pertain to the atomic theory. Einstein mainly worked with executives at the university of Berlin. Born- March 14, 1879. Died- April 18, 1955.

  • Hans Geiger

    Best known for inventing the Geiger counter to measure radiation. He was the first to detect individual alpha particles. Then later on he was able to count beta particles. He was key into the research of electric devices and radiation. He famously worked with Ernest Marsden. Birth- September 30, 1882. Died- September 24, 1945.

  • Ernest Rutherford

    The gold foil experiment is what Rutherford is best known for. This concluded that the atom has a tiny and dense nucleus. He then concluded that the nucleus is surrounded by empty space with tiny electrons floating around. Worked with Hans Geiger and Earnest Marsden after receiving his Nobel prize. Born- August 30, 1871. Died- October 19, 1937.

  • Robert Millikan

    Millikan discovered the value of the electron charge. Most famous for his oil drop experiment. He also was a key researcher in radiation.The photoelectric effect was also credited to him. He worked with some of his students and other scientists at the university of Columbia. Born- March 22, 1868. Died- December 19, 1953.

  • James Chadwick

    James Chadwick is best known for his discovery of the Neutron. He received the Nobel prize in physics for this. He also finalized the MAUD report which basically stated that nuclear weapons were inevitable. This led the US government into theorizing the atomic bomb. Chadwick had Ernest Rutherford as one of his advisers. Born- October 20, 1891. Died- July 24, 1974.