The Role of Electrons
Electrons are found in shells or energy levels, electrons do not just spin around the nucleus. These shells and energy levels are numbered 1,2,3 and 4 and are called K,L,M and N.
Atoms are electrically neutral because the number of protons equals the number of electrons, balancing the positive and negative charges. If this balance is changed then an atom becomes charged and is called an ion. Ions form in a chemical reaction because electrons move from atom to atom.