A negatively charged electroscope is shown in the figure. If a negatively charged rod is placed close to the knob without touching it then what happens to the two leaves?

 We know that unlike charges attract and like charges repel. The electroscope is negatively charged. If a negatively charged rod is placed close to the knob without touching it then the two leaves will move farther apart. 

 When the charge is removed, the electrons return to their original position, and the leaves relax.