2 Light and Quantized Energy An element’s chemical behavior is connected to electron arrangementElectron arrangement and chemical properties are connected to light energyForm of energy that exhibits wave- like behavior….Ex. Visible light, x-rays, microwaves, etc….EM Spectrum – all electromagnetic radiation
3 WavesDescribed by:Wavelength: Shortest distance between 2 equivalent points on a continuous waveAmplitude: height from origin to crestFrequency: how many complete waves pass a point in a given amount of timeHertz; waves per secondSpeed of light (c)- wavelength x speed3.00 x 108 m/s
5 Light – Wave or particle? Max PlanckQuantum – minimum amount of energy that can be gained or lost by an atom…Albert Einstein (1905)Completion of the particle modelEM radiation = stream of tiny particles (bundles of energy) that move like a wave – called photonsPhoton = a particle of EM radiation with no mass that carries a quantum of energy
6 Light – Wave or particle? EM radiation – wave and particle like!!Increasing Energy
7 Atomic Emission Spectra Set of frequencies of the electromagnetic waves emitted by atoms of an elementEach element gives off a unique set of frequenciesQuantum MechanicsElectrons emit certain energy (related to wavelength)Each spectra consists of several “lines” of color…not a continuous range like a visible spectra (rainbow) – there are “black” spaces in between the colors.
9 Real Life Uses Fireworks Neon Signs Bon-Fire (Old Christmas lights) RainbowsScientists can learn what stars are made of by observing the spectrum they emitPhotoelectric panels (solar houses, calculators)