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350
Aristotle
Aristotle disagreed with Democritus's model of the atom. He thought that atoms don't exist. Insteadhe believed that matter was made of fire, earth, water, or air. -
400
Democritis
Democritus was the first scientist to create a model of the atom. He was the first one to discover that all matter is made up of invisible particles called atoms. He created the name "atom" from the Greek word "atomos", which means uncuttable. He also discovered that atoms are solid, insdestructable, and unique. HIs model was just a round solid ball. Democritus didn't know about a nucleus or electrons, all he knew was that everything is made of atoms. -
John Dalton
John Dalton was an English chemist that created the Atomic Theory of Matter. He said in this theory that all matter is made of atoms, that atoms cannot be created nor destroyed and also, atoms of different elements combine in whole ratios to form chemical compunds. -
JJ Thompson
J.J. Thomson discovered the electron, which led him to create the "plum pudding" atomic model. In this model, he thought that the atom was mostly positive, and negative electrons wandered around the atom. -
Ernest Rutherford
Ernest Rutherford was another scientist that changed the atomic model. He felt that J.J. Thomson's model was incorrect, so he created a new one. He created the nucleus, and said that instead of the positive matter being the whole atom, it was just in the middle. He said the atom was mostly empty space and that the electrons surrounded the positive nucleus. -
Neils Bhor
Niels Bohr was a Danish scientist that was a student of Rutherford. He decided to make a new model based off of Rutherford's model, but changed the orbit of the electron. Also, he created energy levels in the atom, where only a certain amount of electrons could fit on one energy level of the atom. -
Erwin Schroedinger
Erwin Scrhodinger was an Austrian scientist that worked with the Quantum model of the atom. He disagreed with Bohr's theory, so he created his own. He thought that the only way to find the location and energy of an electron in an atom was to calculate its probability of being a certain distance from the nucleus.
