Fundamental Particles and Electrical Charge

As Physicists continue to seek fundamental particles, they may have already discovered a fundamental notion.  The erstwhile 'fundamental' particle, the atom, has, in recent centuries, been determined as constituted by protons, electrons, and neutrons, each of which is characterized as possessing as type of 'electrical charge', i. e. 'positive' or 'negative'.  A neutron, too, is constituted by a combination of positive and negative charge, for it possesses a net charge of zero, which is not to be confused with being charge-less.  Furthermore, the constituents of these particles, e. g. quarks, all possess charge.  So, while the subdivision of particles continues, the nature of 'electrical charge' seems to remain unanalyzed.