What is an electroscope you say? An electroscope is a device for detecting electric charge or static electricity. It was first invented jean Antoine Nollet in 1748. His discovery was a breakthrough for the entire science world. It became possible to test objects of there electrostatic attraction and repulsion. An electroscope generally consists of a plate (near the top), a support stand (which connects to the plate and extends through the center of the scope), and a needle which rests upon the support stand and is free to rotate about its pivot. An electroscope of this type is a legit tool which functions by placing a charged object near the top of it. The charged object can be metal rod, a rubber balloon, or something as simple as a finger containing static electricity. .
When operating an electroscope, one, without knowing, charges an electroscope by induction. Technically, the type of induction that is used in the process is electrostatic induction. Induction means to influence without contact. If an object gets charged by induction, a charge is created by the influence of a charged object, but not by contact with a charged object. When one charges an electroscope by induction the electroscope itself ends up oppositely charged to the object used to charge it. .
The electroscope built in class would be considered a simple one at that. It was constructed with the consideration in mind of production cost and convenience. The electroscope constructed fulfilled its job nonetheless. The main difference between our electroscope and an actual real one is that in ours used two foil strips hanging off a hook to demonstrate the charge that occurs. The two foil strips moved apart proving that the experiment worked. The strips moved apart because once they both became the opposite charge of the balloon they were now the both same charge as each other. It was observed that "like charges repel" in that instance.