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                                Pourquoi est-ce que tes cheveux restent debout quand tu frottes un ballon dessus?  
                                Les atoms dans tes cheveux ont perdus les électrons au ballon par le frottement, et maintenant tout tes cheveux ont des charges positives, alors ils se repoussent. 
When you rub a balloon against your hair, several electrons transfer from your hair to the balloon.  Your balloon now has many new electrons (from your hair), so it is charged negatively.  Your hair lost several of it's electrons, which leaves your hair with a positive charge. Your hair stands up and seperates because things that have the same charge repel.  
Some of your hair will stick to the balloon, because your hair is charged positively, and the balloon is charged negatively.  Things with opposite charges are attracted to each other.