The particles were fired at a piece of gold foil. b. most of the particles passed through the foil, indicating that most of the atoms were empty space. c. a very few particles bounced back, indicating the presence of a small, massive, positive nucleus. d. beta particles were used as they are negative. e. the experiment led to the discarding of the "plum-pudding" model of the atom (otherwise known as the "chocolate chip cookie model").