Welcome to Chem. 327The following may be found at http://cyclotron.tamu.edu/watson/ch327:1. Syllabus2. Homework assignments3. Table of constants and conversion factors4. Table of integrals5. Lecture notes 6. Powerpoint slides (after completion of each chapter)7. Solutions to the homework problems (after due dates)8. Solutions to the review questions (prior to each exam.)9. Answers to the examination questions (after each exam.)Help!!!You are strongly encouraged to seek help with things you don’t understand by seeing me outside of class. I am generally available from 9 to 5 on Monday through Friday. You are welcome to drop by my office at any time for help with the lecture/textbook material and the homework. No prior appointment is required, but if you want to be 100% certain of catching me, you may arrange a specific time via telephone, email, or by speaking to me after class.Engr-PhysbldgChem. Engr.ZacheryEngr.Chemistry bldg.CyclotronInst.McD’sRoss StreetUniversity Ave.Spence StreetenterWhy am I taking this course?1. To satisfy a requirement of my degree program.2. To extend, reinforce, and exercise my understandingof basic scientific and mathematical principles and methods.3. To further develop my analytical skills and my ability to understand and solve complex problems.4. To gain knowledge that will contribute to the goal of becoming educated, as opposed to just preparing for a job.How can I get a good grade in this course?(The secret of success)1. Come to class!2. Study the lecture notes.3. Read the corresponding material in the textbook.4. Work the homework problems.5. Seek help with things you don’t understand.6. Keep up to date. ! ! ! !Frontier areas of current researchCosmology – the fundamental properties and evolution of the universeAstrophysics – nucleosynthesis of the heavy elementsSemiconductor technologyNanoscienceLasers and their applicationsHigh temp. superconductorsQuantum computingBiotechnologyovenspectrographU(ν)νBlack body radiation experimentFrequency (1013 s-1)0 1020304050U(ν) (10-17J-s/m3)024682000 K1750 Kvisible lightFrequency distribution of black body radiationAmplitude-40-2002040Amplitude-40-20020X0.0 0.4 0.8 1.2 1.6 2.0Amplitude-80-40040Interference of two waves having slightly different values of kX/λ0.00.51.01.52.02.53.03.54.0Amplitude-6-4-20246A standing wave shown for three different values of tSince a standing wave must have nodes at both ends,L = nλ/2 where n is an integert1t2t3LOne-dimensional standing waveMust satisfy the conditionL = nλ/2where n = integerNecessary condition for the existence of a 3-D standing waveyxλy/2λ/2 = (λx/2 ) cosαααβpropagation directionnodeλx/2nx012345678910ny012345678910dnnThe nxnyplane in n-spacendnThe classical harmonic oscillatorAxHooke’s law: F = −kfxComparison of Rayleigh-Jeans result with experimentFrequency (1013 s-1)0 1020304050U(ν) (10-17J-s/m3)02468T = 2000 KTheory (Rayleigh-Jeans)ExperimentVisible lightFrequency (1013 s-1)0 1020304050U(ν) (10-17J-s/m3)02468T = 2000 KTheory (Rayleigh-Jeans)ExperimentVisible lightExercise: The Show that the Planck formula reduces to the Rayleigh-Jeans formula when hν/kT << 1.X0 10203040506070Amplitude-6-4-20246X0 10203040506070Amplitude-6-4-20246PlottingTips(homeworkProb. 1-1)∆X = 0.1∆X = 5Significant events in the development of quantum theoryI. Discovery of quantization – black body radiationII. Discovery of particle properties of light –Photoelectric effectCompton scatteringIII. Discovery of wave properties of particles –de Broglie wavesIV. Discovery of atomic energy levels –Bohr modelThe photoelectric effectIncident lightEjected electronMetal plateEeνν0BEe= hν−BEphoton= hν = hc/λ0Exercise:The 60.0 keV γ-ray emitted in the radioactive decay of 241Ammay be used to eject K-shell electrons from intermediate Z atoms via the photoelectric effect. 241Am α 239Np + 4He + γa). Calculate the wavelength of the γ-ray. b). Calculate the kinetic energy of a K-electron ejected from a silver atom if the K-electron binding energy is 25.5 keV.Photoelectron SpectroscopyB = hν−EeSpectrum of photoelectrons from CO, CO2, and CH4VUV storage ring at the National Synchrotron Light SourceBrookhaven National LaboratoryCompton scatteringλ' −λ= h/(m0c)[1 − cosθ]incident photonscattered photonscattered electronThe de Broglie hypothesisphλ =Exercise: Calculate the wavelength of an electron with a kineticenergy of 13.6 eV.Light sourceShutter with two slitsScreenLight bandDark bandLight bandDark bandLight bandDark bandLight bandDark bandLight bandDiffraction by a double slitDiffraction pattern obtained by passing a beam of electronsthrough a gold foil.Exercise: Calculate the wavelength of a baseball weighing 200 gand traveling at 90 mi/hr.Schematic diagram of a spectrographThe visible atomic spectra of some elements⎟⎟⎠⎞⎜⎜⎝⎛−=222111nnCνThe Bohr model for one-electron atomsrL−e+ZepE1E2L1L2hνBohr’s quantum rule:hn2πhnL ==Bohr’s hypothesis:The Bohr equations and atomic transitionsZnamZe4πhnrnZEhnemZ2πE20222222022422n==−=−=E0= 13.606 eV a0= 0.529 ÅExercise:Calculate the wavelength of the Lyman alpha transition (n = 2 to n = 1) in a Ne9+ion.Energy levels of the hydrogen atomn=1n=2n=3n=4n=5n=∞E1= −13.6 eVE2= −13.6/4 = −3.40 eVE3= −13.6/9 = −1.51 eVE4= −13.6/16 = −0.850 eVE3= −13.6/25 = −0.544 eVE∞= 03-D plot of the total energy of a hydrogen atomZnarnZEE20220=−=2rZeE2−=ClassicalresultBohr’sresultsPfund seriesBrackett seriesPaschen seriesBalmer seriesLyman seriesSpectral series of the hydrogen atomn = 1n = 2n = 3n = 4n = 5n = ∞−13.6 eV−3.39 eV−1.51 eV−0.85 eV−0.54 eVα10.2 eVSeries limit(ionization energy IE = −E)Orbital electron wave interferencerequirement fora standing wave:nλ = 2πrThe Heisenberg uncertainty principle∆pq∆q ≥ħ/2∆px∆x ≥ħ/2ΔxΔλExercise: Suppose we wish to define the trajectory of an electron in the first Bohr orbit of a hydrogen atom (r = 0.529 Ǻ). We must establish both its position and velocity at a particular instant in time. If we make a measurement to determine the location of theelectron with an uncertainty of ±0.05 Ǻ (i.e., ±10%), what is the minimum simultaneous uncertainty in the velocity of the electron?---Richard Feynman“There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe therewas ever such a time. There might have been a time when