Late Printing Experiment 43 Ohm's Law and Resistance. Introduction It has been known since ancient times that certain materials such as silk, amber, and glass acquire the ability to attract small pieces of paper and cork when rubbed. We now know the reason is that the materials have become electrically charged . The word electric comes from the Greek word for amber, electron.
Electricity is a fundamental force of nature, analogous to gravity.
However, whereas gravitational forces between bodies depends on the mass, electric forces depend on electrical charge. Charge is a basic property of all matter. It may be positive, as in the charge associated with a proton, or negative as in the electron. All matter is comprised of protons and electrons. It is the electric force between protons and electrons in the atom that holds it together.