Why does a rubbed balloon attract paper?
Rubbing can leave a balloon electrically charged. Its charge slightly shifts the distribution of charges in nearby neutral paper, allowing attraction to outweigh repulsion.
- The scientific idea
- Static electricity
- Fields of science
- Physics
How it works
Rub a balloon against hair and it can acquire extra electrons. The charged balloon can then attract other objects. The less obvious part is that the object it attracts does not have to carry an overall opposite charge.
Look closer
A neutral piece of paper contains both positive and negative charges. A nearby charged object shifts their distribution slightly, a process called polarization. The opposite charge is effectively closer than the like charge, so the attraction can outweigh the repulsion. This is why an electrically charged comb can pick up neutral paper scraps. Charging the comb and polarizing the paper are different parts of the same small demonstration.