who discovered that most of atom's mass is in the nucleus
space around the nucleus & predicted the existence of neutrons & discovered that most of an atoms mass is in itâs nucleus which is small, dense positively charged. year 18711937 Bohr Stated that electrons can only travel at specific distances from the nucleus. The electrons were arranged within this substance. 1898: Ernest Rutherfordâs model of the atom was the nuclear model. Atoms of one element differed from that of another atom.