Rutherford's Scattering Experiment

Rutherford's alpha scattering experiment XD

Alpha particle is also helium's nucleus. It's basically shooting alpha particles at a very, very thin gold foil.

i. Most alpha particles pass through the gold foil with little deflection
> The size of atomic nucleus is very small compared to size of atom.
ii. Less than 1% of alpha particles are deflected at large angles more than 90 degree (those are the ones that come near to the gold nucleus)
> mass of atom is concentrated at a small, massive, positively charged nucleus.

[Alpha particle is positively charged so it'll be repelled by positive nucleus when it gets close to it.]