Concept:Rutherford's alpha-particle scattering experiment revealed the presence of a tiny, dense, positively charged core inside an atom, which is called the atomic nucleus.
Explanation:A beam of alpha (
α) particles was fired at a thin gold foil.
Most
α particles passed through with little or no deflection, indicating that most of the atom is empty space.
A few
α particles were deflected by large angles, and about 1 in 8000 bounced back.
This large-angle scattering could only happen if the atom contained a small, heavy, positively charged centre.
Rutherford concluded that all the positive charge and nearly all the mass of an atom are concentrated in a very small region – the atomic nucleus.
Electrons revolve around this nucleus, and the nucleus contains protons and neutrons.
The discovery of the nucleus directly came from this experiment.
Note: The proton was discovered later by Rutherford in 1919, and the neutron by Chadwick in 1932.
The electron had been discovered earlier by J.J. Thomson.
Answer:C. Atomic Nucleus
