The changing atom

The changing atom

1. Greek atom

   • In the 15th Century DEMOCRITUS made the first idea of an atom. He believed that you can only DIVIDE a sample only so many times. Then he thought that you would eventually end up with a particle that COULDN'T be split up any further. He called that particle ATOMOS

2. John Dalton

   • Early 1800's, he made his ATOMIC THEORY he made these following predictions:
     • Atoms are TINY particles that make up elements
     • Atoms CAN'T be divided
     • Atoms from one element are DIFFERENT from those in every other element.
   • The good thing about Dalton's predictions are that most are still true today and alot can be applied to modern day chemostry

3. Joseph John (J J) Thomson

   • !897-1906 Thompson discovered the electron though a series of experiments using CATHODE RAYS. This helped him to show that atoms were made up of SMALLER particles.