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450 BCE
450BC- Empedocles, A Greek Scholar
Empedocles, a Greek scholar in 450BC, was responsible for proposing that Matter was made up of four elements. Those elements were earth ,fire ,air and water. Accordingly, each element has two properties. Empedocles checked that his theories made sense. During this time, he learned that even though you could not see air, it was still there. He decided that air was matter. There is no previous model of matter. -
Period: 450 BCE to
Matter Time Line Assignment
By Ariana Hrlic -
400 BCE
400 BC - Democritus, A Greek
Democritus, a Greek in 400BC decided that matter was made up of particles, he called them atoms. Now not only was there elements, but there was atoms. Elements were created to form other substances. Democritus' idea was not accepted at the time. -
350 BCE
350BC - Aristotle, A philosopher
Aristotle, a philosopher in 350 BC, agreed with both Empedocles and Democritus' ideas. Aristotle believing in both of their ideas had wrote a writing about these ideas had a big enough influence, so much so that Empedocles four element model was accepted for about 2000 years. -
500
500-1600 A.D - Many Alchemists
Many alchemists, in the years 500-1600 A.D had been trying to make Gold from cheap and easy to find materials. they believed that metals grow like plants. They spent lots of time trying to do this eventually until they made symbols for substances (elements and Compounds). They also were responsible for inventing lab equipment (ex: beakers) They accepted the four element model done by Empedocles and did not make any changes. -
1650 - Robert Boyle, A scientist
Robert Boyle, an English scientist 1650, did not agree with the idea of Empedocles' four element model. He came up with a new defention of what an element was. his definition became the modern day definition of what and element is. Robert also did not believe that air was and element. He decided that it was a mixture. -
Late 1700's - Joseph Priestly
Joseph Priestly, In the late 1700's, did not know oxygen was and element but was still the first to isolate it. Antoine Lavoisier recognized this and decided that air is a mixture of two gases. One of those two was oxygen. During this time Henry Cavendish experimented with with mixing metal with acid. -
1800's - Michel Faraday
Micheal Faraday, in the !800's, Even though John Dalton's atomic model could not explain some things, a new model was made. Micheal Faraday found that electric currents could cause a chemical reaction. Atoms could gain an electric charge and form Ions. -
1808 - John Dalton, an English chemist
John Dalton, in 1808, decided on a theory on the reason why some elements are different than each other. Dalton made an atomic model in which he used a sphere to represent an atom. His theory had stated a few things like: all matter being made up of atoms, each element had its own kind of atom and compounds are created when atoms of different elements link onto each other. -
1904 - J.J Thomson
J.J Thomson, in 1904, further and further looked into John Dalton's atomic model. He discovered electrons. He did lots of experiments in which he discovered protons. He made a new model called the raisin bun model. -
1911- Ernest Rutherford
Ernest Rutherford, in 1911, designed an experiment to check Thomson and Nagaoka's Models. This experiment ended up leaving Rutherford amazed and he had described the result as firing bullets. He came up with a new model: The nuclear model.
