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John Dalton 1766-1844
John Dalton was an English chemist, meteorologist and physicist, as he’s recognized for his research on color blindness and the development of the atomic theory. He helped improve the atomic theory by carrying out experiments like the low of multiple proportions and completing the table of atomic weights. Dalton was usually better at visualizing than observing, The results that he came up with are the main 5 for "Daltons Atomic theory": -
J.J. Thomson 1856-1940
J.J Thomson was a British physicist who was accredited for discovering electrons, isotopes and inventing a mass spectrometer. Thomson proved that electrons existence after completing the cathode rays experiment. The experiment was based on estimating the mass of the cathode rays by measuring the heat generated which he concluded that the rays are very light negatively charged particles called electrons. -
The Curies (Pierre and Marie)
The Curies (Pierre and Marie) are a husband and wife team that contributed to the atomic theory. Their accomplishments consist of the creation of a theory of radioactivity, also techniques for separating radioactive isotopes, and the discovery of two elements, radium and polonium. In order to reach these conclusions Marie studied uranium radiations and used piezoelectric techniques created by her husband. Through their testing they found out that the radiations were intense than those from ura. -
Robert Milikan 1868-1953
Robert Millikan was an American physicist who worked on an oil-drop experiment. This experiment measured the charge on an individual electron. Though J.J. Thomson had already discovered the charge to mass ration of an electron but the actual charge and mass were unidentified. Nevertheless they used this experiment to measure the charge of the electron (mass and Avogadro’s number since the relation to the electron charge was identified). -
Ernest Rutherford 1871-1937
Ernest Rutherford the father of nuclear physics is originally from New Zealand. He helped advance the atomic theory with his “gold foil experiment”. Rutherford was determined that the nucleus had mass (dense) and was positively charged according to the experiment performed. Plus he provided a structure of cloud centering with a spherical nucleus showing the density. -
Niels Bohr 1885-1962
Niels Bohr was a danish physicist that played a major role in contributing to the understanding of atomic structure and quantum mechanics. Bohr introduced his model in 1913 and depicted the atom as a small positively charged nucleus with negatively charged electrons orbitting around the nucleus, similar to the sun and our planets. -
Arnold Sommerfeld 1868-1951
Arnold Sommerfeld is a German physicist who contributed to the atomic theory in mathematical approaches. He extended Neil Bohr’s theory by including elliptical paths for electrons. Sommerfeld formulated and equation for the structure of spectral lined and a general quantum theory about it by applying it to the structure of metals. He then worked out a theory of electron in metals with the help of published theories from scientists which lead him to this conclusion. -
Irving Languimer 1881-1957
Irving Langmuir was an American chemist and physicist. He introduced the concept of electron temperature as her built on Gilbert N. Lewis’s cubical atom theory as he outlining his "concentric theory of atomic structure". Languimer invented the diagnostic method for measuring both temperature and density with an electrostatic that is now called Languimer probe. -
Erwin Schrodinger 1887-1961
Erwin Schrodinger is an Austrian physicist who assisted in quantum theory by creating a formula “Schrodinger Equation”. It describes the form of the probability waves that govern the motion of small particles and how these waves are affected by external manipulations. He also constructed the “the electron theory” as Schrodinger resembled the electron cloud as the likely location of the movement of particles. -
Werner Heisenberg 1901-1976
A German physicist who created quantum mechanics. He was able to publish an uncertainty principle which benefited in experiment to have accurate results. With the observations he made he noticed that there could be minor influences on the data that can affect a true value in the conclusion. Heisenberg even developed quantum numbers based on previous theories of Einstein and Planck. He calculated the behavior of electrons, meaning that electrons do not travel neatly as their scattered around. -
James Chadwick 1891-1974
A high achiever in the field of physics as he was nobly acknowledged for discovering neutrons in helping with the development of the atomic theory. The way he approached this unknown particle in the atomic nucleus is by deeply understanding the nuclear fission of uranium-235. When Chadwick detected a neutral particle many believe that it was radiation exertion from the nucleus. But after measuring the velocity of the particles and noticing that the neutral particle has mass similar to the proton -
Murray Gell-Mann and George- Zweig
Murray Gell-Mann and George Zweig are physicists who brought up the idea of “quarks”. Quarks are small bits of matter which is used like building blocks that help explain some complex chemical substances. Quarks were used as a mathematical reasoning for the different patterns in a particle mass.
