What happens when you bring a negatively charged object close to a neutral pith ball?
Please see below.
When you bring a negatively charged object close to a neutral pith ball,
it creates a positive charge (i.e. opposite of negative) on the portion of pith ball nearer the negatively charged object and negative charge on the farthest portion of pith ball.
These positive and negative charges attract the two closer and if they touch each other, positive charges get nullified and both bodies become negatively charged.
Once both are negatively charged, they tend to repel each other.