Question

When an object is touched with the metal top of an electroscope, its aluminium leaves diverge?

Answer 1

When an object is touched with the metal top of an electroscope,its aluminium leaves diverges.

The aluminum leaves diverges because charges in the electroscope is created due to the electric field which is created.

This electroscope can itself gets charged without it is touched with a charged object  this is why the aluminium leaves diverges.