-Aristotle says that Matter is created by four different elements. The elements being Earth, Fire, Water, and Air.
-Democritus states that Matter is created by invisible particles called "atoms."
Period: 500 to
History of the Atom
-John Dalto is called "The Father of Atomic Theory"
states that :
1. atoms are small hard spheres.
2.atoms are invisible.
3.atoms of the same element are the same.
4.atoms of different elements are different.
5.atoms combine in small whole number ratios.
-Discovered the electron Cathode Ray Tube. Used the "Plum Pudding" example.
-Gold Foil Expirament. Discovered the Nucleus.
-Nucleus:very small, very dense.
discovered the charge and mass of an electron.
Planetary Model: electrons orbit the nucleus just like planets orbit the sun.
-discovered the neutron.