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British scientist John Dalton, came up with the atomic theory: that elements are made up of small indivisible particles— atoms. He stated that all atoms of the same element are identical and atoms cannot be created or destroyed. -
Encyclopædia Britannica, inc. (n.d.). John Dalton. Encyclopædia Britannica. Retrieved October 21, 2021, from https://www.britannica.com/biography/John-Dalton. -
Russian chemist, Dmitri Mendeleev, created the first periodic table of elements. He arranged the 70 then known elements by their atomic masses. -
Khan Academy. (n.d.). Dmitri Mendeleev (article). Khan Academy. Retrieved October 21, 2021, from https://www.khanacademy.org/humanities/big-history-project/stars-and-elements/knowing-stars-elements/a/dmitri-mendeleev. -
JJ Thompson was a British chemist who was best known for his discovery of the electron. He used a high vacuum cathode ray tube to discover the electron. -
Admin. (2020, October 6). Cathode Ray Experiment by JJ.Thomson (CRT) - explanation & uses. BYJUS. Retrieved October 21, 2021, from https://byjus.com/chemistry/cathode-ray-experiment/. -
Ernest Rutherford was a New Zealand born chemist who said that an atom is mostly made up of empty space. He said that most of the mass of an atom was in the nucleus. The nucleus is positively charged and the outer part of electrons is negatively charged. He also discovered alpha and beta particles through his gold foil experiment. -
Encyclopædia Britannica, inc. (n.d.). Rutherford model. Encyclopædia Britannica. Retrieved October 21, 2021, from https://www.britannica.com/science/Rutherford-model. -
Niels Bohr is a very influential chemist. He was born in Denmark and was best known for making the Bohr model. One of his theories stated that atoms can only occupy certain spaces. This explained the spectral lines of Hydrogen. -
Encyclopædia Britannica, inc. (n.d.). Bohr model. Encyclopædia Britannica. Retrieved October 21, 2021, from https://www.britannica.com/science/Bohr-model. -
He is perhaps one of the most influential scientists to ever live. Everyone has heard of him and his e=mc^2 equation. He also created the theory of relativity and the theory of quantum mechanics. -
Bembenek, S. (2018, March 27). Einstein and the Quantum. Scientific American Blog Network. Retrieved October 21, 2021, from https://blogs.scientificamerican.com/observations/einstein-and-the-quantum/. -
American physicist, Robert Millikan, was the first to accurately measure electric charge. He then obtained an accurate value for Planck’s constant. He became the vice chairman of the NRC and helped with war research when WW1 began. -
This French chemist played an important role in the discovery of quantum mechanics. He made the controversial discovery that electrons can behave as both waves and particles, thus explains their peculiar motion. -
Encyclopædia Britannica, inc. (n.d.). Millikan oil-drop experiment. Encyclopædia Britannica. Retrieved October 21, 2021, from https://www.britannica.com/science/Millikan-oil-drop-experiment. -
The nobel prize in physics 1929. NobelPrize.org. (n.d.). Retrieved October 21, 2021, from https://www.nobelprize.org/prizes/physics/1929/broglie/biographical/.