91Ó°ÊÓ

An electric charge is an entity or a property of a particle that causes it to get influenced via experiencing a force when placed inside an electric or magnetic field.The charge due to electrons is mainly what is referred to as electric charge and one electron carries a charge of $1.6\mathrm{x}{10}^{-19}\mathrm{C}$. Like charges repel each other and unlike charges attract each other

When the two strips are peeled, the negatively charged electrons flow to the rest of the tape roll from the stripped part. So, the tapes that are stripped are both negatively charged at the same time on their sticky side and will repel for sure. Now, if the sticky side of one is pasted on the shiny side of the other and then stripped off forcefully separating them in the process, then there will be a flow of electrons again. But this time there will be a net positive charge build-up which will cause the attraction between the two strips. Thus, the transfer of negative charge from one strip to other causes one to be positive and then subsequent attraction.