Join my Physics Tutoring Class: https://zphysicslessons.net/physics-tutoring If you do AQA A Level Physics Astrophysics, watch this video: https://www.youtube.com/watch?v=5l787rt7cy4 This is video is suitable for OCR A Level Physics, Edexcel, Eduqas, International CIE 9702 syllabus A Level Physics. Chapters: 00:00 Intro 00:25 Star Formation 02:33 Hertzsprung Russel Diagram 03:50 Chandrasekah Limit 04:25 Energy Levels 10:25 Emission and Absorption Spectra 12:19 Diffraction gratings 15:22 Diffraction experiment 18:41 Wien's Displacement Law 19:55 Stefan-Boltzmann Law 21:53 Practice Problem