1. By static in case of electricity we mean imbalance of charges at the surface of a body. When we rub a surface we dislocate some of the charges and sue to this, electrical neutrality is hindered and imbalance of charges make static electricity.
2. An object with a suspected static electric charge is brought near the metal plate or ball of the electroscope. Electrical charges move to the metal and down to the foil leaves, which then repel each other. Since each leaf has the same charge (positive or negative), they repel each other.
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