- Rutherford scattering and the demise of the plum pudding
- In 1804, John Dalton agreed with Democritus that matter was made up of tiny spheres known as atoms that couldn't be broken up, but he reckoned that each element was made up of a different type of atom.
- Nearly 100 years later, J.J.Thomson discovered that electrons could be removed from atoms.
- So Dalton's theory wasn't quite right (atoms could be broken up).
- Thomson suggested that atoms were spheres of positive charge with tiny negative electrons stuck in them like plums in a plum pudding.
- That "plum pudding" theory didn't last very long though.
- In 1909, Ernest Rutherford and his men tried firing alpha particles at thin gold foil.
- Most of them just went straight through, but the odd one came back at them, which was very strange for Rutherford and his men.
- Being a pretty…