When did Ernest Rutherford publish the results of the gold-foil experiment, which showed that scattering is caused by a rigid, dense core at the centre of the atom - the nucleus?

1911

The correct answer is Option (2) - 1911

In 1911, Ernest Rutherford published the results of the gold-foil experiment, providing evidence for the existence of the atomic nucleus. This groundbreaking experiment showed that most of the mass and positive charge of an atom are concentrated in a small, dense core at its center, which Rutherford termed the nucleus. This discovery revolutionized the understanding of atomic structure and laid the groundwork for modern atomic theory.