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The alchemists first introduced the idea of the four elements: earth, fire, water, and wind. The alchemists were a group of people that lasted until the late 1700's. -
Plato discovered there are only 5 solid shapes. He was convinced atoms came from these 5 shapes. -
Democritus was a philosopher that first introduced the idea of an atom. -
Robert Boyle came up with the definition of an element: any substance that can't be broken down. He also helped prove the four elements wrong. -
Antone discovered that all matter is always conserved, even if they undergo chemical changes. -
The Billiard Ball Model explains the atoms can lock together to make elements. People at the time did not know about atoms, so tight thought atoms were balls. -
John Dalton explained all matter is made of atoms. He also said the atom is the smallest building block. -
Amedeo Avogadro said: two equal volumes have the same number of molecules. -
Dimitri Mendeelev invented the modern periodic table. This table ordered the elements based on weight. -
JJ Thompson discovered the Electron, the negatively charged part of an atom. He also made the plum pudding model. -
Robert Millikan discovered the positively charged part of the atom: protons. -
The Plum Pudding model explains that the electron is negatively charged, it shows the negative electrons surrounded by positively charged matter. -
Albert Einstein proved the existence of atoms using math, completely revolutionizing science. -
Pierre. and Marie were a couple. that discovered that radiation is in a form of waves. Radiation waves are constant. -
Ernest Rutherford discovered that an atom is radioactive. -
The Solar system is a model based off of our solar system. It explains that the sun is the nucleus, and the electrons are the planets and parts moving around it. -
Neils Bohr discovered if an electron is taken away, it gives off radiation. He also discovered the atom ands won a Nobel Prize. -
Henry Mosely said the atomic number equals the number of protons in the atom. He also said there were more undiscovered elements. -
Erwin Shrodinger was able to use the Bohr model to predict the likelihood of finding an electron at a certain position. -
The electron cloud model explains that it is impossible to know exactly where an electron is at one moment. -
James Chadwick discovered the neutron, the uncharged part of and atom. -
Werner Heisenberg discovered that a particles position can never be known exactly.