Properties of the Nucleus
(i) Nucleus is a small, heavy, positively charged portion of the atom and located at the centre of the atom.
(ii) All the positive charge of atom (i.e. protons) are present in nucleus.
(iii) Nucleus contains neutrons and protons, and hence these particles collectively are also referred to as nucleons.
(iv) The size of nucleus is measured in Fermi (1 Fermi = 10–13 cm).
(v) The radius of nucleus is of the order of 1.5×10-13cm to 6.5×10-13cm i.e. 1.5 to 6.5 Fermi. Generally the radius of the nucleus (rn) is given by the following relation, rn = ro (=1.4 × 10-13cm)×A1/2
This exhibited that nucleus is 10-5 times small in size as compared to the total size of atom.
(vi) The Volume of the nucleus is about 10-39 cm3 and that of atom is 10-24 cm3, i.e., volume of the nucleus is 10-15 times that of an atom.
(vii) The density of the nucleus is of the order of 1015 gcm-3 or 108 tonnes cm-3 or 1012 kg/cc. If nucleus is spherical than,
Density = mass of the nucleus/volume of the nucleus = mass number/6.023×1023 × 4/3 πr3