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Democritus introduced the idea of the atom (that everything is made up of much smaller particles)
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Thomas Jefferson engineers the Louisiana Purchase.
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John Dalton (1766-1844) proposed a theory that suggested that all matter is composed of solid atoms with different masses and properties. -
Michael Faraday (1971-1867) discovered electromagnetic induction using an induction ring.
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Eugen Goldstein (1850-1930) discovered canal rays- positively charged ions that are accelerated towards a perforated cathode.
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JJ Thomson (1856-1940) discovered the electron and proposed a new model of the structure of an atom called the plum pudding model. this model shows negatively charged particles floating in a positively charged “soup”. -
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Robert Millikan (1886-1953) discovered that electrons have a fixed, measurable charge and his work allowed scientists to be able to calculate the mass of an electron.
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Ernest Rutherford (1871-1937) discovered alpha and beta rays and the nucleus of an atom. the discovery of the nucleus led hm to be able to make the nuclear model of the atom. -
Neils Bohr (1885-1962) proposed a model of the atom where each electron could only occupy its specific orbit around the nucleus, which is called the solar system model. -
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Werner Heisenburg (1901-1976) formulated quantum mechanics in terms of matrices and significantly contributed to atomic theory.
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Edwin Schrödinger (1887-1961) formulated an equation that could calculate the energy levels of electrons and proposed the electron cloud model which shows a “cloud” of space around the nucleus where the electron(s) could be. -
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James Chadwick (1891-1974) proved the existence of neutrons in the atom. Neutrons are subatomic particles that are found in the nucleus along with protons.