Slide 1Electromagnetic RadiationSlide 3Slide 4Slide 5The Spectrum of Electromagnetic RadiationSlide 7Slide 8Slide 9The Photoelectric Effect - IThe Photoelectric Effect - IISlide 12Photons and the Photoelectric EffectSlide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Photoelectric Effect -ISlide 22Slide 23Photoelectric Effect - IILight and AtomsEnergy Level DiagramSlide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Light Has MomentumSlide 46Heisenberg Uncertainty PrincipleSlide 48Slide 49Slide 50Slide 51Slide 52Slide 53Quantum Numbers - IQuantum Numbers - IIQuantum Numbers - IIISlide 57Slide 58Slide 59Slide 60Chapter 7: Quantum Theory and Atomic Structure7.1 The Nature of Light7.2 Atomic Spectra7.3 The Wave - Particle Duality of Matter and Energy7.4 The Quantum - Mechanical Model of the AtomElectromagnetic Radiation•WAVELENGTH - The distance between identical points on successive waves. (  )•FREQUENCY - The number of waves that pass through a particular point per second. ()•AMPLITUDE - The vertical distance from the midline to a peak, or trough in the wave.cvFig. 7.1Fig. 7.2Fig. 7.3The Spectrum of Electromagnetic Radiation•The wavelength of visible light is between 400 and 700 nanometers•Radio, TV , microwave and infrared radiation have longer wavelengths (shorter frequencies), and lower energies than visible light.•Gamma rays and X-rays have shorter wavelengths (larger frequencies), and higher energies than visible light!Calculation of Frequency from WavelengthProblem: The wavelength of an x-ray is 1.00 x10 -9 m or 1 nm, what is the frequency of this x-ray? If the wavelength of long-wavelength electromagnetic radiation is 7.65 x 104 m, what is the frequency of this long-wavelength radiation used to contact submerged nuclear submarines at sea?Plan: Use the relationship between wavelength and frequency to obtainthe answer. wavelength x frequency = speed of light!Solution:frequency(cycles/sec) = speed of light wavelength(m)frequencya)b) frequencyCalculation of Frequency from WavelengthProblem: The wavelength of an x-ray is 1.00 x10 -9 m or 1 nm, what is the frequency of this x-ray? If the wavelength of long-wavelength electromagnetic radiation is 7.65 x 104 m, what is the frequency of this long-wavelength radiation used to contact submerged nuclear submarines at sea?Plan: Use the relationship between wavelength and frequency to obtainthe answer. wavelength x frequency = speed of light!Solution:frequency(cycles/sec) = speed of light wavelength(m)frequency = = 3.00 x 1017 cycles/sec3.00 x 108 m/s1.00 x 10 - 9 ma)b) frequencyCalculation of Frequency from WavelengthProblem: The wavelength of an x-ray is 1.00 x10 -9 m or 1 nm, what is the frequency of this x-ray? If the wavelength of long-wavelength electromagnetic radiation is 7.65 x 104 m, what is the frequency of this long-wavelength radiation used to contact submerged nuclear submarines at sea?Plan: Use the relationship between wavelength and frequency to obtainthe answer. wavelength x frequency = speed of light!Solution:frequency(cycles/sec) = speed of light wavelength(m)frequency = = 3.00 x 1017 cycles/sec3.00 x 108 m/s1.00 x 10 - 9 ma)b) frequency = = 3.92 x 103 cycles/s 3.00 x 108 m/s7.65 x 104 mThe Photoelectric Effect - I•Below the threshold energy, nothing occurs !•Above the threshold, the kinetic energy of the ejected electrons is proportional to the frequency of the light.•Also, when above the threshold, as intensity of the light increases, so does the number of ejected electrons.•All metals experience this effect, but each has a unique threshold frequency.The Photoelectric Effect - II•Albert Einstein –Theorized Photons–Won Nobel prize - 1921•Photons have an energy equal to: E = h•h = Plank’s Constant, and is equal to:6.6260755 x 10 - 3 4JsecDemonstration of the Photoelectric EffectFig. 7.7Photons and the Photoelectric Effect•Einstein also stated that the change in the photon’s energy was equal to the ejected electron’s energy.•Therefore, the photon’s energy equaled the electron’s kinetic energy added to the electron’s binding energy • ETotal = Electron binding + Electron Kinetic energyCalculation of Energy from FrequencyProblem: What is the energy of a photon of electromagnetic radiation being emitted by radio station KBSG 97.3 FM ( 97.3 x 108 cycles/sec)?What is the energy of a gamma ray emitted by Cs137 if it has a frequencyof 1.60 x 1020/s?Plan: Use the relationship between energy and frequency to obtain the energy of the electromagnetic radiation (E = hv).Solution: EKBSG =hv \\Calculation of Energy from FrequencyProblem: What is the energy of a photon of electromagnetic radiation being emitted by radio station KBSG 97.3 FM ( 97.3 x 108 cycles/sec)?What is the energy of a gamma ray emitted by Cs137 if it has a frequencyof 1.60 x 1020/s?Plan: Use the relationship between energy and frequency to obtain the energy of the electromagnetic radiation (E = hv).Solution: EKBSG =hv = (6.626 x 10 -34Js)(9.73 x 109/s) = 6.447098 x 10 -24JEKBSG = 6.45 x 10 - 24 JCalculation of Energy from FrequencyProblem: What is the energy of a photon of electromagnetic radiation being emitted by radio station KBSG 97.3 FM ( 97.3 x 108 cycles/sec)?What is the energy of a gamma ray emitted by Cs137 if it has a frequencyof 1.60 x 1020/s?Plan: Use the relationship between energy and frequency to obtain the energy of the electromagnetic radiation (E = hv).Solution: EKBSG =hv = (6.626 x 10 -34Js)(9.73 x 109/s) = 6.447098 x 10 -24JEKBSG = 6.45 x 10 - 24 JEgamma ray =hv =Calculation of Energy from FrequencyProblem: What is the energy of a photon of electromagnetic radiation being emitted by radio station KBSG 97.3 FM ( 97.3 x 108 cycles/sec)?What is the energy of a gamma ray emitted by Cs137 if it has a frequencyof 1.60 x 1020/s?Plan: Use the relationship between energy and frequency to obtain the energy of the electromagnetic radiation (E = hv).Solution: EKBSG =hv = (6.626 x 10 -34Js)(9.73 x 109/s) = 6.447098 x 10 -24JEKBSG = 6.45 x 10 - 24 JEgamma ray =hv = ( 6.626 x 10-34Js )( 1.60 x 1020/s ) = 1.06 x 10 -13JEgamma ray = 1.06 x 10 - 13JCalculation of Energy from WavelengthProblem: What is the energy