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Cavemen thought that matter was anything that was solid that stone tools could be made out of.
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The earliest chemists they produced and sold valuable metals such as gold, silver, and cooper.
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Iron was combined with carbon to make steel for stronger tools. It was also in this time period that people first discovered how to extract iron from rocks and melt it into pots and pans.
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Democritus believed that all matter could be divided into tiny, indivisible bits called “atoms”
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Antoine Lavoisier, he developed a system that was used for naming elements. He even named oxygen and hydrogen. He is also considered one of the very first people to name sulfur as a element and not a compound.
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Dalton's theory he proposed was the indivisible unit of an element is the atom.
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He believed and discovered that electrons resided within a spherical of uniform positive change. This theory is also known as the Plum Pudding Model
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Hantaro Nagaoka's theory was that a alternative model of the atom where a positively charged center is surrounded by a great number of electrons that are revolving.
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Rutherford demonstrated that the existence of a positively charged nucleus that contains almost all of the mass of the atom.
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He proposed that fixed orbits in the form of a circle, orbits around the nucleus for electrons.
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James Chadwick's atomic theory was that he discovered beryllium atoms with alpha particles. It caused an unknown radiation. This became the neutron.
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In the current model that we use today, electrons take up space(orbitals) around the nucleus determined by their energies
