1. Electrons move between the rod since the electrons are the only charge carriers which are free to move.
2. The particles move from from "Y" to "X" since the electrons are the only charge carriers which are free to move. The positive charge on rod x is due to a deficit of electrons while the negative charge on rod Y is due to the excess of electrons. When the rods come together, the electrons move from "Y" to "X" since the electrons are the only charge carriers which are free to move.