Atoms are the foundation of chemistry. They are the basis for everything in the Universe. In this second unit of class 11 chemistry, we will learn the discovery of subatomic particles- electrons, neutrons, & protons, atomic models of J.J Thomson's, Rutherford's, Bohr's. We will learn the dual nature of light and electron, quantum mechanics, quantum numbers. We will also learn the rules for writing the electronic configurations of atoms.
Curated by: Khan Academy India - English (37 videos)
Why do hot objects glow and why couldn’t classical physics explain it? In this video, we explore the mystery of black body radiation and the observations that challenged long-held ideas about energy. We’ll walk you through how scientists studied the radiation emitted by heated objects, where classical theory failed, and how Planck’s bold quantum hypothesis solved the puzzle. This isn’t just a physics concept, it’s a breakthrough that introduced the idea of energy quantization, forming the basis of quantum theory in modern science. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/science/class-11-chemistry-india/xfbb6cb8fc2bd00c8:in-in-structure-of-atom?lang=en Timestamps: 00:20 - Blackbody radiation definition 00:43 - Blackbody radiation explanation 01:16 - Classical physics prediction about blackbody radiation 01:43 - Where classical physics failed 02:05 - Change of wavelength with temperature 02:21 - Planck’s theory of quantization 02:31 - Quanta/photon 03:35 - Colour of object at different temperatures 04:26 - Photoelectric effect Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Aman Saurav