Exciting Electrons

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Exciting Electrons. Can electrons move between energy levels? How do we know?. Parts of a Wave: energy traveling through space!. Horizontal distance from crest to crest . Vertical distance from zero (node) to crest of wave. What about Frequency?. - PowerPoint PPT Presentation


<p>Exciting Electrons</p> <p>Electrons as Waves of EnergyCan electrons move between energy levels?How do we know?</p> <p>Click to see how electrons behave Parts of a Wave: Wavelength (-Lambda) </p> <p>Horizontal distance from crest to crest Meters or nanometers are the unitsParts of a wave: Frequency ( Nu)cycles past a given point in a fixed amount of time Hz or s-1 are the unitsWavelength and frequency are inversely related. </p> <p>Inverse RelationshipSpeed of Light RelationshipConstant (c) = 2.998 x 108 m/secc = 2.998 x 108 m/sec = </p> <p>Example ProblemCalculate the frequency of light that has a wavelength of 4.25 x 10-9m. 7.1 x 10 16 /sec = c = 2.998 x 108 m/sec = 4.25 x 10 -9 m () </p> <p>Shorter frequency Longer frequencyWavelength and Light RelationshipWhen visible light passes through prism, it separates out into colors based on wavelength. </p> <p>Electron TransitionWhen electrons move from higher to lower energy levels, they release energy in the form of radiation . sometimes in the visible spectrum.Electron releases energy (photon).</p> <p>Energy has a particular wavelength.</p> <p>Wavelength may be part of the visible light spectrum.Electronic TransitionThis energy emitted is called a quantum of energy (E). ONLY emitted when electrons transitions downward.This process is known as electronic transition.</p> <p>Energy of Photons RelationshipPlanks Constant (h) = 6.626 x 10 -34 J*s Energy of photons = Planks x frequencyE = h </p> <p>E = 6.626 x 10 -34 J*s </p> <p>Example ProblemCalculate the energy of light that has a frequency of 1.5 x 1015 Hz.(Hz =sec-1)</p> <p>E = 9.95 x 10-19 J E = 6.626 x 10 -34 J*s E = 6.626 x 10 -34 J*s (1.5 x 1015 per sec) Atomic Emission Spectrumpassing electric current through gas in a tube energizes the electrons which emit light</p> <p>each transition produces a line of specific wavelength in the spectrum</p>