https //phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom en.html The Build an Atom interactive simulation from PhET allows you to explore the structure of atoms and understand how their properties are determined by the arrangement of protons, neutrons, and electrons. Here’s … Continue reading https //phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom en.html