Ch+27+-+Quantum+Physics

The study of Quantum Physics began with the discovery of the electron and the charge of the electron by JJ Thompson and the charge of the electron by Robert Millikan. Thompson discovered the electron after many experiments with cathode rays. The charge was found by Millikan and the oil drop experiment.

__**Thermal Radiation**__
 * Thermal Radiation says that any any object at any temperature emits radiation.
 * P=oAeT^4
 * o = 5.6696E-8
 * Varies in temperature and wavelength
 * Low Temperature = Inferred Rays
 * Higher Temperatures = Red to White, This is light we can see
 * Blackbodies
 * Objects that can absorb all radiation, this includes light


 * __Plank's Hypothesis__**
 * Max Planck[[image:Max_planck.jpg width="188" height="279" align="right" caption="Max Plank (Availible through WikiCommens)" link="http://en.wikipedia.org/wiki/File:Max_planck.jpg"]]
 * German Physicist
 * Energy is distributed in discrete amounts
 * E =nhf
 * n = quantum number
 * h = Planck's constant = 6.626E-34
 * Energy is quantized

__**X-Rays**__
 * __Photoelectric Effect__**
 * Light hits a metallic surface and the metal releases electrons
 * These electrons can be used to start a current in a circuit
 * This is a link to the explore learning activity on the photoelectric effect
 * [|Photoelctric Effect Gizmo]
 * The shorter the wavelength the more energy (faster) the electrons are released with
 * Stopping Potential
 * Voltage applied in the opposite direction of the electrons
 * With enough the current can be dropped to zero
 * Work Fuction
 * Minimum energy that electron is attached to a metal
 * Formula for photoelectric effect: KE = hf - ø
 * ø = Work Funtion
 * Cutoff Frequecy
 * When hf › ø
 * c = (cut off frequency)(wavelength)
 * Produced when high speed electrons suddenly slow down
 * Characteristic X-Rays are the Rays released with the highest intensities
 * The are formed from the electrons going back to the 1st energy level
 * Diffraction
 * Must be through a tiny slit
 * 2dsinØ = ml ← (l is lambda or wavelength)
 * The Compton Effect
 * An X-Ray photon hits an electron
 * Momentum and energy conserved
 * Scattered X-Ray has less energy


 * __Uncertainty Principle__**
 * It is impossible to measure the exact position and speed of a particle
 * xp › h/4(pi)
 * Et › h/4(pi)