How did Rutherford and Bohr develop their theory?
Rutherford had conducted experiments in which he shot relatively large, charged particles (alpha particles) at a thin gold foil. He found that most of the particles passed directly through the foil, but some came off at odd angles, as though they had been deflected. From these results, Rutherford concluded that each atom was mostly empty space, but also contained a dense region–a central mass, which his alpha particles could not pass through. He also concluded that this central mass must have a positive charge, to deflect the positively charged alpha particles. Rutherford and Bohr pictured the arrangement of the atom’s parts to look like our solar system. At the center of every atom is a nucleus, which is comparable to the sun in our solar system. Electrons move around the nucleus in “orbits” similar to the way planets move around the sun.
