In this video Prof Arno Smets talks about the behavior of electrons and the states they can obtain within an atom depending on their energy level. He then explains the way certain atoms contain different state electrons, and how this affects their behavior.
You will find the chapter associated to the lecture below the videos.
Solar Energy by TU Delft OpenCourseWare is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Based on a work at https://ocw.tudelft.nl/courses/solar-energy/.