(a) The atomic nucleus consists of two types of elementary particles, viz. protons and neutrons. These particles are collectively called nucleons.
(b) The electrons surround this nucleus to form the atom.
(c) This structure of atom was revealed by the experiments of Rutherford in which a beam of α-particles were made to strike a thin gold foil.
(d) Nucleus can be regarded as a small spherical volume situated at the centre of atom.
(e) Most of the mass of the atom is concentrated in the nucleus.
(f) Nucleus has a positive charge.
