Quantum Physics Complete Guide

Quantum Physics Complete Guide Photon Particle of light Intensity + Formula Power per unit area I = P/A Units: W/m² The Photoelectric Effect The emmision of electrons from a metal when electromagnetic radiation of high enough frequency falls on the surface. Threshold Frequency (f₀) Minimum frequency of light needed to eject electrons fromt he surface of the metal Classical Theory Light acts as a wave and the energy of a wave depends on its amplitude (intensity) not its frequency. Work Function E = hf ɸ = hf₀ Einstein's Photoelectric Effect Equation Eᵀ = Eᵀ hf = ɸ + Eᴹªˣ hf = hf₀ + Eᴹªˣ De Broglie Hypothesis All particles can behave like waves whose wavelength is given by ƛ = h/p (h: Planck's constant, p: momentum of particle) Wave Matter All moving particles have a "matter wave" associated with them whose wavelength is the De Broglie wavelength. Wave Particle Duality Both matter and radiation have dual nature. They exhibit both particle and wave properties. De Broglie Wavelength Formula ƛ = h/p = h/mv Photon Momentum Formula p = h/ƛ Particle momentum Formula p = h/ƛ = mv Limitation Of The Nuclear Model Of The Atom According to classical physics, an orbiting electron is accelerating, radiating energy. Electron losses energy when orbiting. 1. Spiral In 2. Would radiate energy as light in continuous spectrum of colors. - Emission spectra consists of only well defined discrete wavelengths. Emission Spectra Low pressure gas is energized by applying a potential difference across it causing it to heat up. Absorption Spectra Light shone through a cool low pressure gas. Erwin Schrodinger Made use of De Broglie's hypothesis to develop the first truly quantum theory of the atom using wave mechanics. Werner Heisnberg Won a nobel prize for development of his uncertainty principle which identifies a fundamental limit to the possible precision of any physical measure. Uncertainty Principle 1. Both the position and momentum of a particle cannot be precisely known at the same time 2. Both the energy state of a particle and the amount of time it is in that energy sta