Question 2 on test 1

We know about electrons even though they are extremely small. Ernest Rutherford did the Gold Foil Experiment in the early 1900s.  Rutherford fired alpha particles at the gold foil and most went through the gold foil but some bounced off at sharp angles. This experiment and many others like it concluded that atoms had both positively and negatively charged particles. This experiment and many others like it and other chemical and nuclear reactions that there are definitely electrons, protons, and neutrons.