Thomson's contribution to the atomic theory was the discovery that negatively-charged electrons were embedded within a positively-charged "soup". Later on Rutherford performed the gold foil experiment which altered Thomson's contribution. What were the conclusions of Rutherford's Gold Foil Experiment? Group of answer choices a. The atom is made up of mostly empty space with a tiny, dense, positively-charged nucleus. b. The atom is mostly empty space, with negative charge concentrated at the center. c. The atom is mostly empty space, with positive charges spread evenly across it. d. The atom is mostly empty space. No other conclusions could be made.