In 1911, rutherford carried out his experiment by bombarding a very thin gold foil (0.0004 mm thick) with high-speed a -particles (He+2ions) emitted from Radium and observed that:
i. Majority of a -particles continued their straight path without any deflection.
ii. Some, which passed very close to the atom were deflected from their path through large angles.
iii. Very few of them returned back (1 in 20,000) in opposite direction.
Rutherford Atomic Model:
Rutherford’s model of the atom consists of two-part:
1. Nucleus: It is a small Positively charged part of the atom. It is situated at the center and carries almost the entire mass of the atom. The nucleus contains neutrons and protons and hence these particles are collectively called nucleus.
2. Extranuclear part: This part of the empty part of the atom. In this part, electrons revolve at a very high speed in a fixed part called orbits or shells. As the nuclear part of the atom is responsible for the mass of the atom, the extranuclear part is responsible for its volume.