Atom is the smallest and fundamental part of matter.
Rutherford studied the scattering of a-particles from thin gold foils. Scattering of the a-particles by a thin gold foil suggest the present of positively charged nucleus at centre of atom which is known as nucleus.
The nucleus consists of protons and neutrons, they are called nucleons.
The nucleus of an atom represented as \(_zX^ A\), i.e. nucleus of X contains Z protons and (A - Z) neutrons.
The size of the nucleus is of the order of fermi. 1 fermi = 10-15 metre
The radius of nucleus is given by R = R0A1/3, where R0 = 1.2 fermi and A = mass number.
Nuclear Force
The force which are responsible for tied the neutron and proton in the nucleus is known as nuclear force.
