Electricity Activity 3-12-09

In physics/math class we did three different activity's to learn about electricity. The first activity was to rub a balloon against someones head, then try to pick up pieces of paper with the static, and then seeing if it would stick to someones jacket. Our observations was that the balloon picked up the paper but would not stick to a jacket. My hypothesis for this is that the static energy created by rubbing the balloon against the hair could not stay attached to something else when it already picked up the pieces of paper.
The second activity we did was to get two pieces of tape about ten inches long and stick it on the table. Then quickly pull them both off and see what they did. We found that the two pieces of tape moved away from each other. My hypothesis for this station is that the electromagnetic force which is that like atoms repel. I believe that it is electromagnetic force because the pieces of tape repelled away from the other piece of tape.
The third activity we did was to cut two pieces of tape about ten inches each. Then stick one piece of tape to the table and put the other piece of tape on the other piece of tape. Next quickly pull the two pieces off. We found that the two pieces of tape attracted to each other. I believe that the tape was attracted to each other because some of the electrons went to the other piece so there was a positive and negative, which caused it to come together.
Questions:
Why does the balloon not stick to the jacket? It has other times before for me...