Ernest Rutherford performed an experiment in 1911 to know more about the structure of atom. He made a narrow beam of α particles (obtained from polonium) to strike an extremely thin sheet of metal such as gold and silver. A fluorescent sheet was placed behind the metal sheet and the α-particles after passing through the metal sheet were made to strike the fluorescent screen. He performed a series of experiments and gave the following observations:-
a) Most of the α-particles pass through the sheet of the metal without suffering any deflection in their path indicating that most of the space in an atom is empty.
b) A very small number of α-particles get deflected through larger angles and some even get deflected backwards. It indicated the presence of a heavy and positively charged particle at the center in each atom with a volume of few fractions of the total
