This is an activity that breaks down a lab that I found in a textbook years ago. The new GA standards ask our students to make models and this lab helps them understand the difference in mass of electrons and protons. You will need clay or playdoh, small paper clip and a scale. I demo this for some of my classes but for others I let them do all the work. Some students will need calculators for the math. The main objective is to see that a proton or neutron is 2000 times bigger than an electron. The video embedded explains and you can google others. This is something that I reference throughout the unit. I also, added an extension for those students who want to create their own atom.