Despite how awkward it really is as a model, look at the Bohr model of an atom. In the two-dimensional representation, most of the outer parts of the model are where the electrons exist, while the inner-most area is the cluster of protons and neutrons. Look into the Rutherford gold foil experiment for more support of this answer.
and the other part:
proton mass = 1.7 x 10-27 kg (1 atomic mass unit)
electron mass = 9.1 x 10-31 kg (0.00055 atomic mass units)