JJ thompson, rutherford, bohr, i believe rutherfors did the gold foil experiment disproving the plum pudding model from thompson and bohr said the nucleus was positively charged surrounded by electrons that travel in orbits around the nuclei (like the jimmy nuetron symbol)
No one made the atom. Ernest Rutherford (from New Zealand, yay!) was the first person to split to atom, and Im sure countless other scientists have played roles in characterising the atoms properties.
thank you this helped:P