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300
Aristole's discovery(mid 300's BC)
He discovered that things and objects were made of different amounts of earth, water, air, fire and etc. But Aristole did not believe atoms exsited. -
400
Democritus's discovery(400 BC)
He basically said and explained that you will eventually come to a point where you couldn't cut the atom in half anymore. And even though he strongly felt this way, he had no way to prove it. Also, he thought atoms came in different sizes and shapes. And he thought salt atoms had spikes becasue it tasted sharp. -
Dalton's dicovery(1808)
He discovered oxygen and carbon combined makes two compounds. He also said and discovered compounds consisted of atoms of different elements combined together. His theory said that the atoms of each element were different from one another, and they had different masses. The method he used was his atomic theory he came up with.(The Dalton model)He thought the atoms were tiny,indivisble, indestructible particles & each has a certain mass and chemical behavior that was determined by type of element -
Thomson's discovery(1909)
He discovered that electrons are much smaller than atoms. He used the _______ method to discover this. He thought if you took an atom and split it open you would see electrons inside of it. He also came up with the plum pudding model. -
Bohr's discovery(1913)
He discovered the Bohr model. He thought the electrons were spining around the nucleus in circle orbits. And at the time, he developed his own theories too. -
Rutherford's Discovery(1911 and 1919)
He discovered the Nuclear Model. He thought the nucleus was positive and electrons were around it. This model was also called the Gold Foil Model. And in 1919 he discovered protons. -
Heisenberg(1927) and Schrodinger's(1926) discovery
Heisenberg discovered the Quantum Mechanical Model. And Schrodinger showed that electrons were like hyper active flies and had a particular path. They determined that the only way to describe the location of an electron in an atom is through probability distribution.
