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Aristotle lived in the 500's B.C. He believed that there was no limit to how many times matter could be divided.
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John Dalton's theory was that all atoms of the same element have the same mass, and atoms of different elements have different masses, that compounds contain atoms of more than one element, and in a particular compound atoms of different elements always combine in the same way. To come to his theory, Dalton measured masses of elements that combine when elements form.
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Thomson discovered subatomic particles and electrons by using an electric cord to positively charge a disk, and negatively charge another.
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Nagaoka suggested a central nucleus and that electrons orbit around the atom
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Ernest Rutherford stated that atoms have a nucleus that is dense and positively charged. He also said that electrons revolve around the nucleus. Rutherford was Marsden's teacher.
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Marsden aimed alpha particles at a sheet of gold to see how the gold atoms would affect the alpha particles. Marsden believed that the alpha particles would only be slightly deflected. Marsden discovered that the closer the particles came to the center of the gold atoms, the more deflected they became. This lead to the discovery of the nucleus. Ernest Marsden was Ernest Rutherford's student.
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Discovered that each electron has a specific amount of energy. Energy levels- Possible energies an electron in an atom can have. An electron in an atom can move from one energy level to another when the atom gains or loses energy. To come to his conclusions, Bohr worked with Ernest Rutherford.
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Louis de Broglie is famous because he proposed the idea that particles move and have some waves like electrons. Broglie came to his conclusions by studying the atomic theories of the scientists of his time.
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Shrodinger created mathematical equations to describe the motion of electrons. He was able to come up with his equations by using Bohr's model and Broglie's concept.
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Described atoms by means of formula connected to the frequencies of spectral lines. Proposed Principle of Indeterminancy - you can not know both the position and velocity of a particle.
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James Chadwick was able to confirm the existence of nuetrons which have no charge. To prove this, he made an experiment
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Conducted the first controlled chain reaction releasing energy from the atoms nucleus.
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Domocritus lived in 500 B.C. He came up with the name atom through the work of discourse.
