Who discovered nucleus of an atom?

The nucleus of an atom was discovered by Ernest Rutherford. Here are the steps he took in his discovery:

1. Rutherford performed an experiment known as the Gold Foil Experiment, or Geiger-Marsden experiments, which began in 1908.
2. In this experiment, he bombarded a thin sheet of gold with positively charged alpha particles.
3. He expected the alpha particles to pass straight through the gold foil, based on the 'plum pudding' model of the atom that was accepted at the time.
4. However, he found that some of the alpha particles were deflected at large angles, while others even bounced back.
5. This led Rutherford to conclude that the positive charge in an atom is not spread out evenly, but is concentrated in a small central area. He called this area the 'nucleus'.
6. Rutherford's nuclear model of the atom proposed that the atom is mostly empty space, with its mass and positive charge concentrated in the nucleus.
7. This discovery was a significant step in the development of atomic physics and quantum mechanics.