Final answer:
An electroscope is a device used in physics demonstrations and laboratories. When a positively charged glass rod is brought near the electroscope, the leaves separate due to like charges repelling. When the glass rod is touched against the electroscope, electrons are transferred, resulting in a positive charge on the electroscope.
Step-by-step explanation:
An electroscope is a device used in physics demonstrations and laboratories. It consists of gold foil leaves hanging from a metal stem, which is insulated in a glass-walled container. When a positively charged glass rod is brought near the tip of the electroscope, electrons are attracted to the top, leaving a net positive charge on the leaves. The like charges in the leaves repel, causing them to separate.
When the glass rod is touched against the ball of the electroscope, electrons are attracted and transferred, reducing the net charge on the rod and leaving the electroscope with a positive charge. The excess charges are evenly distributed on the stem and leaves of the electroscope once the glass rod is removed.