Atomic Theories

John Dalton believed when you cut things down, until you can not cut anymore, is when you get atoms. He believed matter formed of small pieces, that couldn't be cut into smaller parts, where also atoms. John did a lot of work with color blindness also. He believed the elements (water,fire,earth and air) where made of tiny particles called atoms. He believed the difference in the elements were caused by the difference in the atomic mass. Soon all this was changed when J.J. Thomson descovered the electron. Unlike John's theory of an atom being somewhat like a round ball, J.J. proved that an atom was broken down into many small compartments like a puzzle. J.J. used a cathode ray tube to discover that atoms not only have electrons but also have negative and positive charges. J.J. changed the atomic model forever.