An electroscope is a simple device used to detect electric charge. It typically consists of a metal rod and two thin leaves made of metal (often gold or aluminum) that hang from the bottom of the rod. When an electroscope is charged, the leaves will change position based on the nature of that charge.
Here's how the leaves of an electroscope behave when the device is charged:
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Charging by Contact: If a charged object touches the electroscope, electrons will either be transferred to or from the electroscope. This transfer of charge will cause the leaves to either repel each other or draw closer together based on the charge imparted.
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Same Charge Causes Repulsion: If the electroscope receives a charge, both leaves will have the same charge. Since like charges repel, the leaves will move apart and spread away from each other. The more charge there is, the further apart the leaves will spread.
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Different Charge Causes Attraction: If a negatively charged object is brought near (but not touching) the electroscope, it will induce a separation of charges within the electroscope, causing the leaves to move slightly as the charges redistribute. However, if the electroscope is grounded by touching it while a charge is near, it can lose some of its electrons and become positively charged, leading to the leaves repelling each other again if they become the same charge.
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Discharge: If the electroscope is allowed to discharge (by grounding it or allowing it to touch another neutral object), the leaves will return to their original position, generally hanging straight down.
In summary, when the electroscope is charged, the leaves will spread apart due to repulsion if they acquire the same type of charge.