Kinetic EnergyWhat happens to the kinetic energy of an atom when it absorbs a photon?It does nothingKinetic energy doesn’t change due to electron moleculesBlack Body RadiationIncandescence not consistent with Maxwell equations, wave theory.Most intense emission in the infrared regionLittle or no emissions in UV.E=nhvExample of question: How much energy is emitted by ___ photons at a wavelength of ____nm?Energy Level DiagramShows electron transitions (movement of electrons between energy levels) = absorption of energy = emission of energyThe Bohr Model of the H AtomBohr’s atomic model postulated the following:The H atom has only certain energy levels, which Bohr calls stationary statesEach state is associated with a fixed circular orbit of the electron around the nucleusThe higher the energy level, the farther the orbit is from the nucleusWhen the H electron is in the first orbit, the atom is in it’s lowest energy state, called the ground state.The atom does not radiate energy while in one of it’s stationary stateThe atom changes to another station state only by absorbing or emit a photonThe energy of the photon (hv) equals the difference between the energies of the two energy statesWhen the E electron is in any orbit higher than n=1, the atom is in an excited stateStrengthsAccurately predicts energy needed to remove an electron from an atomAllows scientists to begin using quantum theory to explain matter at atomic levelLimitationsDoes not account for spectra of multi-electron atomsMovement of electrons in atoms is less clearly defined than Bohr allowedApplying Bohr’s equationE=-2.Where z is the charge of the nucleus. For hydrogen Z=1 so:Practice Problem:A hydrogen atom absorbs a photon of UV light and its electron moves from the n=2 to the n=4 energy level. CalculateThe change in energy of the atomThe wavelength (in nm) of the photon that could make this changeThe WaveLinear WavesNotes= regions of standing waves that experience no displacementWavelength, λ = 2LHarmonic frequencies:L= n λ/2For n=2½: no nodes, so no standing waveElectrons as wavesElectrons behave like circular waves oscillating around a nucleusNo defined stationary endsStable circular waves of circumferencede Broglie WavelengthCombine mass-energy equivalence and energy of a photonE= mc2 E = hvλ = h/muParticle Nature of Photonsλ= h/mc= h/pP= h/ λHeisenberg’s uncertain principalIt is impossible to know both position and momentum for a particle with wave behaviorImportant question on exam:An electron moving near an atomic nucleus has a speed of ____ m/s ±1%. What is the uncertainty of its position?Ĥ ψ= EψPart of the Schrodinger equation is the “trident” or wave functionA mathematical description of the electron’s matter-wave in three dimensionsWe normally refer to this as an “atomic orbital”Shapes and Sizes of OrbitalsRadial Distribution Plot:A graphical representation of the probability of finding an electron in a thin spherical layer near the nucleus of an atoms Orbitals:Spherical shape with electron densities highest near nucleusElectron distribution exhibits maxima at finite distance from nucleusTypes of orbitalss- sharpP-principled diffusef- Fundamentalg- The next after fundamentalh- The next after g. . . . (Alphabetical)Progression or OrbitalsI=1 represents s orbitalsI=2 represents p orbitalsI= 3 represents d orbitalsI = 4 represnets f orbitalsWhat orbital has the lowest potential energy? 1sThe three 2p orbitalsThree p orbitals in each shell with n>_ 2; nodes at nucleusThe Five 3d orbitalsFive d orbitals in each shell with n>- 3; nodes at nucleusThere are 7 f orbitals1-s2-p4 d8- for f*what f orbitals look likeCHEM 111 1nd Edition Lecture 9Outline of Last Lecture I. Problems with Rutherford’s ModelII. Calculating the Wavelength of Spectral Lines III. Emission Transitions of HydrogenOutline of Current Lecture II. Review from last lectureIII. Energy Level DiagramIV. Bohr’s Atomic ModelV. The Wavea. Linear Wavesb. Electrons as wavesc. de Broglie Wavelengthi. Particle Nature of PhotonsVI. Heisenberg’s uncertain principalCurrent LectureReview from last lecture:Kinetic Energy-What happens to the kinetic energy of an atom when it absorbs a photon?o It does nothingo Kinetic energy doesn’t change due to electron moleculesBlack Body Radiation-Incandescence not consistent with Maxwell equations, wave theory.o Most intense emission in the infrared regiono Little or no emissions in UV.E=nhv-Example of question: How much energy is emitted by ___ photons at a wavelength of____nm?These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Energy Level Diagram- Shows electron transitions (movement of electrons between energy levels)-  = absorption of energy-  = emission of energyThe Bohr Model of the H Atom Bohr’s atomic model postulated the following:- The H atom has only certain energy levels, which Bohr calls stationary stateso Each state is associated with a fixed circular orbit of the electron around the nucleuso The higher the energy level, the farther the orbit is from the nucleuso When the H electron is in the first orbit, the atom is in it’s lowest energy state, called the ground state.- The atom does not radiate energy while in one of it’s stationary state- The atom changes to another station state only by absorbing or emit a photono The energy of the photon (hv) equals the difference between the energies of the two energy stateso When the E electron is in any orbit higher than n=1, the atom is in an excited state- Strengthso Accurately predicts energy needed to remove an electron from an atomo Allows scientists to begin using quantum theory to explain matter at atomic level- Limitationso Does not account for spectra of multi-electron atomso Movement of electrons in atoms is less clearly defined than Bohr allowedApplying Bohr’s equationo E=-2.o Where z is the charge of the nucleus. For hydrogen Z=1 so:Practice Problem: A hydrogen atom absorbs a photon of UV light and its electron moves from the n=2 to the n=4 energy level. Calculate- The change in energy of the atom- The wavelength (in nm) of the photon that could make this change The Wave Linear Waves- Notes= regions of standing waves that experience no displacement- Wavelength, λ = 2L- Harmonic frequencies:o L= n λ/2o For n=2½: no