Which of these observations rutherford determine that atoms have tiny, dense, positively charged nuclei? which of these observations rutherford determine that atoms have tiny, dense, positively charged nuclei? most of the alpha particles in his experiment passed directly through the gold foil. some materials naturally give off alpha particles. a few of the alpha particles in his experiment were deflected from the gold foil at large angles. none of the alpha particles in his experiment could travel through lead.