History of the Atom
Greek’s Democritus coined the term atom by saying that all things are made of atoms. The Greek's only had 4 elements: Earth Wind Fire Water
Dalton’s Atomic Theory All matter is composed of atoms Atoms of a given element are identical in size, mass, and other properties Atoms can not be subdivided, created, or destroyed Law of Conservation of Matter Law of Definite Proportion Law of Multiple Proportion
Modern Atomic Theory The same as Dalton’s Theory except we had to modify statement 2 and 3 Atoms are made of Protons, Neutrons, and Electrons Atoms of the same element have the same number of protons but can have a different size or mass because of Isotopes
Joseph John Thomson Discovered the Electron
Ernest Rutherford Discovered the Nucleus (protons)