Geiger-Marsden experiment

- They aimed beams of positively charged particles at thin gold foil - These particles should have passed straight through however many bounced back (were deflected) as the central nucleus is positive and repelled the positive alpha particle beams - As most went through, most of the atom is empty space - Atoms have a central positively charged nucleus with most of the mass as only a few were deflected - It proved that most of the mass is concentrated in a central nucleus and it proved that the nucleus is positive