An alpha particle is an ionized helium nucleus, consisting of 2 protons and 2 neutrons bound together. when alpha particles are beamed toward a thin metal foil, most of them pass through, undergoing a small deflection, while a small fraction of them bounce back at much larger angles in excess of 90 degrees relative to their incoming direction. the reason this happens is that o most alpha particles avoid the electron clouds around the metal atoms and experience only a small deflection, while a few (positively charged) alpha particles penetrate and get strongly attracted by an electron cloud and experience a larger deflection. o most alpha particles hit electrons, causing a small deflection, while a few alpha particles bounce off a nucleus and experience a larger deflection o a few alpha particles hit a nucleus, causing a small deflection, while a most alpha particles bounce off an electron and experience a smaller deflection o most alpha particles hit just one electron, causing a smal deflection, while a lew alpha particles hit multiple electrons and experience a larger deflection d |