What is the radius of the hydrogen atom? How has this answer changed over time? Quantum mechanics is fun and cool. Tablet math is tedious. If anyone is trying to solve a homework problem and just googled this, a_0= 0.53e-10 m Does anybody actually read these things? The textbook is Principles of Quantum Mechanics by Professor R. Shankar. Here is a link to his YaleOpenCourse course: https://www.youtube.com/watch?v=KOKnWaLiL8w&list=PLFE3074A4CB751B2B You can join my Patreon if you like. I post a new, patron-only video each month. https://www.patreon.com/acollierastro