Van De Graff Observations

In class we conducted many experiments using a Van De Graff. A Van De Graff takes electrons from a brush on the bottom of it and moves them up to the other brush and then expels them into the metal dome.
When balloons were blown toward the Van De Graff they were initially attracted. Then at some point when the bubbles got near the Van De Graff they started to repel. At one point a human chain was formed with the last and first person touching the Van De Graff. When a person not in the chain touched a person in the chain they were shocked. I think this was because the energy from the Van De Graff was transferred to the people in the chain and when an outsider touched one of them the shock was a transfer of energy. In one test napkins were placed on the Van De Graff. When the machine was turned on the napkins all flew off except for one. The one that stayed on the machine was attracted to it. I think this is because the napkins had the same electric charge so they repelled each other but when there was just one then there wasn't other napkins to repel from so it was attracted to the strong pull of the Van De Graff. In another experiment paper strips were taped to the sides of the Van De Graff. When the machine was turned on, the paper strips flew up. I think this is because the machine and strips had the same electrical charge because the energy came from the Van De Graff. The strips flew up because they were trying to repel the other strips and the machine. When the wand was put near the Van De Graff the strips were attracted to the machine. In one experiment cheerios were place on top of the dome. When the Van De Graff was turned on the cheerios flew off the dome. I think this is because some of the energy from the dome was transferred to the cheerios which gave them the same electrical charge. Since they had the same electrical charge they repelled each other.

Questions
How does the wand affect the electrical charge of other objects?