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)
How were electrons discovered? In this video, we explore the experiment that led to the discovery of the electron, and the key observations that changed atomic theory forever. We’ll walk you through J.J. Thomson’s cathode ray experiment, the effects of electric and magnetic fields on the rays, and how these findings revealed the presence of negatively charged particles. This isn’t just a history lesson, it’s a step-by-step breakdown of how careful observation and clever experimentation unlocked the subatomic world. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:structure-of-the-atom/x46dd29ce84a663ea:models-of-an-atom/e/atomic-structure?lang=en Timestamps: 0:03 Cathode ray experiment 1:00 Deflection in electrical and magnetic field 1:48 demonstration of cathode ray mass 2:21 Cathode ray experiment observations 3:21 q/m ratio 4:28 milliken's oil drop experiment, canal rays 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