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in 450 BC Empedocles created the 4 element model the model contend fire, water, air and earth. How he tested his ideas were through experements
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in 400 BC
a second Greek named Democritus said that matter is made up of tiny particles and they can't be broken down any more. He also said called particles atoms after the Greek word atomos witch means indivisible.
He called it the atomic model. -
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In 300 BC a Greek philosopher named aristotloe believed in the 4 element model despite the atomic model was around
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in 1650 a English scientist Robert Boyle did not believe in the 4 element model He came up with a different definition for the word element he said it was a pure substance that can't be chemically broken down and this would become the modern definition for an element. Also he believed that air was not an element rather a mixture
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In 1750 Joseph Priestly, Antoine Lavoisier and Henry Cavendish.
Joseph and Antoine worked to find out that why air is not an element they concluded that air is a mixture because it has to be made up of 2 different gases. While they were figuring why air is not a element Henry Cavendish mixed metals with acid and he created hydrogen -
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In the 1800 a chemist named John Dalton modified the current atomic model to include some more info on what the elements are made of and how they react to each other.
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In 1904 a guy named JJ. Thomson revised the atomic model and added that all atoms have something call electrons witch are little negative charges. He also concluded that all atoms have a heavier charge called protons and he called it the raisin bun model
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a teacher named Ernest Rutherford tested the raisin bun model some more by aiming a alpha particle gun at some gold foil and some of the particles bounced back to him and then he concluded that all atoms have a tiny dense core called a nucleus witch deflected the particles and contained protons and he called this the nuclear model witch we still go by today
