Rutherfords Experiment

Rutherford (a New Zealander) fired Alpha particles at an extremely thin gold foil.

He expected them to go straight through with perhaps a minor deflection.

Most did go straight through, but to his surprise some particles bounced directly off the gold sheet!

 

What did this mean?

 

Rutherford hypothesized that the positive alpha particles had hit a concnertated mass of positive particles, which he termed the nucleus.