What are the observations in Rutherfords Alpha Scattering Experiments?
He observed that alpha particles can scatter (bounce) backwards off of matter. If matter was evenly distributed, the high energy particles should go through it like “a 15 inch shell through tissue paper” to paraphrase Rutherford. The fact that they bounced back meant that the the charged matter (protons) must be distributed in small dense clusters so that the alpha particles (helium nuclei) hit these charges like a billiard ball and, if hit directly, could bounce straight back. This lead him to the understanding that atoms have a small central charged nucleus surrounded less densely by negative charges (electrons). It was, in some sense, the beginning of nuclear physics.
