Compare the properties of electrons, protons and neutrons.

What important information is furnished about the nucleus of an atom by the alpha particle scattering experiment of Rutherford?

An element has atomic number 13 and an atomic mass of 27.

(a) How many electrons are there in each atom of the element?

(b) How are these electrons distributed in the various energy levels?

What are the limitations of J.J. Thomson's model of the atom?

What are the limitations of Rutherford's model of the atom?