Video Tutorial: Isotopes

I purchased Camtasia Studio over the summer and have used it to create tutorials for teachers that use our school's gradebook program.  I just discovered a feature in the software that allows quizzes to be embedded in a video.  I create Power Points all the time that are designed as mini tutorial/review sessions for my students.  Camtasia has a plugin for Power Point that allows you to capture screen video and audio.  So I decided to do a screencast for my isotope review/tutorial and then embed questions that students can answer to check their understanding.  I'm very pleased with the results.  I think I might do screencasts in the future for subs to run during an absence. It will be like I'm in the classroom, when I'm not.