Atomic models

Atomic models

1. 1. Democritus

   • Experiment:
     • Democritus called his discovery because he believed that the atom was unbreakable into smaller parts. To initially find the atom, Democritus conducted a simple experiment that can still be done today. What he did was take a simple seashell and break it in half.
       • Period:
         • 460 BC
           • Personal life
             • Democritus remained unmarried for the entirety of his life, dedicating himself to the study of various philosophical doctrines. He is said to have lived over a hundred years by certain sources, even though according to Diodorus Siculus, he died at the age of 90, in around 370 BC.
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2. Dalton

   • Experiment:
     • Dalton's experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each individual gas exerted while occupying the same space. In 1803 this scientific principle officially came to be known as Dalton's Law of Partial Pressures.
       • Period:
         • 8500-7900 BC
           • personal life
             • British chemist John Dalton was born in Eaglesfield, England, on September 6, 1766, to a Quaker family. He had two surviving siblings. Both he and his brother were born color-blind. Dalton's father earned a modest income as a handloom weaver.
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3. Thomson

   • Experiment:
     • J. J. Thomson discovered the existence of electrons. He did this using a cathode ray tube, which is a vacuum-sealed tube with a cathode and anode on one end that create a beam of electrons travelling towards the other end of the tube.
       • Period:
         • 1897
           • Personal life
             • Thomson married Rose Paget, one of his students, in 1890. They had one daughter, Joan, and one son, George Paget Thomson, who went on to become a physicist and win a Nobel Prize of his own. ... In addition to being awarded the Nobel Prize in 1906, he was knighted in 1908 by King Edward VII.
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4. Rutherford

   • Experiment:
     • Ernest Rutherford's experiment of shooting alpha particles through a thin sheet of gold, and discovering that some were deflected, proved that an atom is actually a small dense nucleus surrounded by orbiting electrons.
       • Period:
         • 1912
           • Personal life
             • Ernest Rutherford (1871- 1937) was a New Zealand born British- physicist who was known as the father of nuclear physics and discovered Beta particle, alpha particle, and the Rutherford model. He won many awards such as the Nobel Prize in Chemistry in 1908 and Copley Medal in 1922. He also invented a receiver to detect radio waves.

5. James Chadwick

   • Experiment:
     • Chadwick put a piece of beryllium in a vacuum chamber with some polonium. The polonium emitted alpha rays, which struck the beryllium.
       • Period:
         • 1935
           • personal life
             • James Chadwick was born in the small town of Bollington, England, UK on October 20, 1891. His parents were Joseph, a railway storekeeper, and Anne, a domestic servant. When he was 11, James won entry to the prestigious Manchester Grammar School. Unfortunately, his parents were too poor to afford the modest school fees.

6. Bohr

   • Experiment:
     • Bohr Atomic Model : In 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. ... To remedy the stability problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy.
       • Period:
         • 1913
           • personal life
             • Niels Bohr was born on October 7, 1885, in Copenhagen, Denmark, to mother Ellen Adler, who was part of a successful Jewish banking clan, and father Christian Bohr, a celebrated physiology academic. The young Bohr eventually attended Copenhagen University, where he received his master's and doctorate in physics by 1911.

7. Erwin schrodinger

   • Experiment:
     • The modern atomic theory states that atoms of one element are the same, while atoms of different elements are different.
       • period
         • 1940
           • personal life:
             • Schrödinger led an unconventional personal life, marrying Annemarie Bertel in 1920 and also concurrently living with his mistress, Mrs. Hilde March. He had three children. He died of tuberculosis, aged 73 on 4th January 1961.