Final answer:
The electrostatic series helps to determine if an object will gain or lose electrons when in contact with another material, while using an electroscope can determine the exact charge. The leaves of an electroscope charged by contact with a positive charge will show divergent or convergent reactions when other charged objects are nearby.
Step-by-step explanation:
The electrostatic series helps to determine the charge of an object by comparing the tendencies of different materials to lose or gain electrons. When an electroscope is charged positively, its leaves repel each other due to like charges. Bringing other charged objects near the knob of the electroscope can cause the leaves to either diverge more or converge, depending on the charge of the object. If a positively charged object is brought near, the leaves diverge more because like charges repel (electrostatic repulsion). Conversely, if a negatively charged object is brought close, the leaves may fall together slightly because opposite charges attract, indicating that the object has a charge opposite to that of the electroscope.
Electrostatic induction can also be used to determine the charge of an object without making direct contact. When a charged rod is brought near a neutral object, it induces an opposite charge on the side closest to the rod and a like charge on the opposite side, which can be detected with an electroscope. Tribo-electric charging, where different materials gain or lose electrons when in contact, can be understood by referencing a tribo-electric series. Materials higher on this series tend to lose electrons and become positively charged, while those lower tend to gain electrons and become negatively charged.