The atom has a very small, heavy, positively charged nucleus with lots of empty space around it. He made no conjecture about electrons, orbits, etc.
Ernest Rutherford was the man you are thinking of. He was the first person to 'split the atom'.
Rutherford
The gold-foil experiment
In 1920, Rutherford gave the name proton to the positively charged particles in the nucleus of an atom.
split the atom
The nuclear atom was discovered by Ernest Rutherford. He did it with a gold foil experiment.
When Rutherford discovered the positive charge in an atom was concentrated in the nucleus, the neutron had yet to be discovered. There are no neutrons in Rutherford's model.
Rutherford discovered in the early 1900s that most of an atom's mass is located in its nucleus.
Rutherford imagined the atom to be a particle with a thickly concentrated positive nucleus and electrons moving around it.
Rutherford pictured the atom as a miniature solar system, with a dense positively charged nucleus at the center and electrons orbiting around it in fixed paths. This model is known as the Rutherford model of the atom.
Ernest Rutherford is credited with the development of the "Rutherford Model" of the atom, which proposed that the atom consisted of a small, dense nucleus containing positively charged protons orbited by negatively charged electrons. This model was developed in 1911 based on experiments conducted in his laboratory.
Rutherford discovered the atomic nucleus, proposed a nuclear model of the atom also he isolated nitrogen.