Rutherford's experiment using a beam of alpha particles aimed at a sheet of gold foil led him to conclude that an atom's mass is located in the atom's nucleus.
In his experiment, he bombarded a thin gold foil with alpha particles.
He found that most of the alpha particles passed through the foil while a few of them were deflected back.
To explain this, he suggested an atomic model(nuclear model) in which an atom is made up of a small positively charged center or nucleus.
The mass is concentrated in the nucleus.
A large space containing electrons further surrounds the nucleus.
