Chemistry: Understanding Electrons

www.mindbites.com for a bundle of videos on Early Atomic Theory. For an even broader bundle of videos that cover Early Atomic Theory and Atoms, Molecules, and Ions, check out www.mindbites.com . To search for topic-specific help in our library of 400+ video products for Chemistry, please refer to our Chemistry category at: www.mindbites.com . To check out our full Chemistry video course, with 300+ videos included, refer to: www.mindbites.com . Or, for access to this single video, go to: www.mindbites.com . After JJ Thomson’s experiment to determine the charge to mass ratio for electrons, Robert Millikan devised an experiment to find the actual mass and charge of electrons. Robert Millikan won the Nobel Prize in 1923 for what is now known as The Millikan Oil Drop Experiment. In this experiment, Millikan atomized oil into small droplets in a box with two charged plates in it. The first plate had a small hole through which gravity would pull the droplets down. If and electric field was added to the plates, the neutral droplets would still fall through the hole. However, if the air between the plates is ionized, the electrons are removed from the air and attach to the oil droplets. The now negatively charged droplets are repelled from the positively charged bottom plate and can be made motionless with a proper balance of the coulomb force between the plates. With this information, and the known charge to mass ratio of an electron, Prof. Yee will show you how Millikan …