I have been following your posts and how you patiently started from atom and its constituents: Viz, electron, proton and neutron. You elaborated on electronic configuration and its influence on the properties of engineering material. Now you have linked all these to the flow of electrons which leads to the flow of charges when external pressure is applied by means of battery. Most interesting is the way you distinguished current from voltage and the explanation of potential difference using two point charges. Thanks for the clarity you enhanced using diagrams. It has really helped some us that are not mathematicians to follow up. Looking forward to your next post.