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A British chemist concluded that each elemet have exactly same atoms. He also thought that each element's atoms mass is different. he thought of them as small balls.
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The Britis scientist J.J. Thomson found the electron. he makes a new model with the atom being a positively charged sphere with electrons within it. he described it being like a muffin with the berries being like the electrons.
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A japanese physicist Hantaro Nagaoka porposed a model of the atom with a positively charged sphere in the middle with electrons orbiting it.
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Britsh physicist Ernest Rutherford saw that the atom is mostly empty space. Electrons randomly orbit the positively charged nulceus.
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Danish physicist Niels Bohr proposed a model that showed eletrons moving in specific layers and not randomly. he said that atoms asorb or give off energy when the electrons move from one shell to another.
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James Chadwick dicovered why atoms where heavier than the total mass of their electrons and protons. he dicovered that atoms also have neutrons.
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The current model that we use today. Electrons form a negatively charged arond the nucleus like a cloud. The elactrons move so fast that is impossible to tell where the elactrons are.
