History of an Atom

History of an atom:

John Dalton:

• Atoms are solid spheres
• Different atoms/spheres are made of different elements

1897: J.J Thompson:

• Atom is a ball of positive charge with electrons stuck in it
• Plum pudding model

1909:Ernest Rutherford:

• Gold Foil Experiment
• He fired positively charged alpha particles at a thin gold sheet.

Expecting:

• Most alpha particles pass through the gold…