A physics student believes that she has found an experimental way to apply some mysterious "third" type of charge to a plastic sphere that is hung by a string. The student observes that the sphere is gently attracted to both a positively-charged rod and a negatively-charged rod. The student concludes that the sphere is charged neither positive nor negative, but charged in some other "third" way that attracts both positive and negative charges.
Which arguments below could be correctly used to convince the student that they arrived at a faulty conclusion?
Select TWO answers.