Answer:
B) Rutherford's gold foil experiment
Explanation:
Rutherford's gold foil experiment
Rutherford conducted an experiment in which he took a thin gold particle film on which he passes alpha- particles. He noticed that:
Most of the alpha particles get through the film and can be detected by the detector.
Around small portion of the alpha particle deflected at small angles.
A very very few alpha particle (approximately 1 out of 1 million alpha particles) just retraced their path which means come back from the center.
He concluded that:
Most of the space of the atom is empty and in the center of the atom , there is solid mass which is the cause of the alpha particles to come back. He gave the term nucleus to this solid mass.