When Paul blew bubbles at the Van De Graff they were repelled away from it. I think that happened because the bubbles had the same charge as the charge that the Van De Graff produced. When we formed a human chain that touched the Van De Graff no one got shocked because when Paul turned it on the charge was sent equally through everyone, but if someone let go and touched someone else the charge was sent to someone else, thus shocking them. When Paul put a napkin on the Van De Graff it flew away. I think that happened because the napkin had the same charge as the charge that the Van De Graff produced. When Paul put many napkins on the Van De Graff they didn't fly away. I think that happened because the napkins were thicker and needed more time for it to be charged. When Paul put paper strips on the Van De Graff they stood up because the paper had the same charge as the charge that the Van De Graff produced, thus causing the paper to repel from the machine and itself. When Paul put cheerios on the Van De Graff they flew away. I think that happened because the cheerios had the same charge as the charge that the Van De Graff produced.