This only happens when you touch it before lifting it. Let s figure out how the electrophorus works. The cutting board charges up negatively. Think of the soda can. When you touch the rim, the charges from the rim jump on your hand.
Charges are like little balls.
They can be pushed around, transferred from one place to another, selected according to type or mixed all together. There is, however, a physical device called electroscope built for this. Let s get familiar with it. Charge up the golf tube with the plastic bag and observe the aluminum foil in the soda bottle when you bring it near. Cut two strips of aluminum foil about 3 mm by 1.0 cm.