An ebonite rod is a classic tool for demonstrating the triboelectric effect, where certain materials become electrically charged through friction. Ebonite—also known as hard rubber—is produced by vulcanizing natural rubber with a high sulfur content (often 30–40%), creating a rigid, electrically insulating material with a strong tendency to gain electrons. When an ebonite rod is rubbed with a material like fur or wool, electrons transfer onto the rod’s surface. This leaves the rod negatively charged, while the rubbing material becomes positively charged. The effect arises from differences in how tightly each material holds onto its electrons, a property described by the triboelectric series. Once charged, the rod can attract lightweight neutral objects like paper bits or even bend a thin stream of water. This happens because the electric field of the rod polarizes nearby molecules, creating temporary charge separation that results in attraction. Despite the dramatic effects, the total charge involved is tiny—often just a few nanocoulombs—yet it is sufficient to visibly demonstrate electrostatic forces. Each rod is 6" long. Sold as a set of 3.
