You rab a plastic pen through your hair. Explain carefully but heietly why the pen attracts pieces of alumimum foil and why it attracts pieces of paper.

It is because by rubbing a plastic pen by hair a charge is induced into the pen due to friction between the pen and the hair.

Explanation:

When we rub a pen in dry hair since the pen is electrically neutral due to rubbing a charge transfer occurs between the two materials. The charge transfer occurs on account of the different electron affinity of the two materials. The pen becomes negatively charged on the account of electrons are transferred to it, and when it is brought near any other substance such as paper bit's the paper bits become electrically oppositely charged on account of induction thus resulting in attraction between then materials.