Static Electricity

Today I did a lesson with my students on static electricity.  We learned about atoms and electrical charges. The students participated in two hands-on activities.  In the first activity, students tested the effects of rubbing  a plastic ruler with cloth (transferring electrons) and then holding it over salt and pepper.  They determined that the plastic ruler was negatively charged and the pepper was positively charged because the pepper "flew up" to the ruler, and the salt was negatively charged because it did not move.  They learned that like charges repel and unlike charges attract.  Here are a few pictures of this activity.

  

After testing the ruler with salt and pepper, they blew up a balloon and watched to see if the balloon after being rubbed by a cloth (causing it to become negatively charged) would "attract" torn pieces of paper.  Almost all of the the students predicted that the balloon would pick up and move some of the paper.  Their predictions were confirmed.  

My students love science.  They really enjoy exploring and problem solving.  Several students came up with new questions while doing these experiments.  One of the things that they were the most curious about was investigating which types of materials would be more likely to become negatively charged after being rubbed and what materials were good materials to rub them with.  I thought these were very clever questions that showed how engaged the students were with these activities.