Applying What
You’ve Learned
Let’s see if you really understand how the rules for charged objects work. Look at the charges on each pair of balloons and predict whether the balloons will attract each other, repel each other, or do nothing. Explain why in each case.

No doubt you’ve noticed that when a comb is charged with static electricity, it acts differently than when it was neutral even though it looks the same. That’s not so strange when you think about it. The electrons and protons responsible for the charges are so small that they are invisible to our eyes.

So how do we tell if something is charged? You could always touch it, but if it had a big charge you could get shocked! Since our other senses can’t easily detect static electricity, we need to build something that can safely tell if an object is charged.

 
Check your predictions and explanations on the inside back cover.