Slide 1Why does Neon Glow?Dilemmas/Flaws of Atomic StructureWave PropertiesClicker 6.1:Speed of WavesRadiation (aka Energy)Max PlankSample ProblemWhat can we learn from White light?Atomic SpectraBohr Model of Hydrogen AtomQuantum StaircaseQuantum StaircaseBohr Spectral LinesCalculating Energy of ElectronsLimitations of Bohr’s ModelWave Behavior of MatterWave Behavior of MatterThe Wavelength of a BaseballThe Uncertainty PrincipleQuantum MechanicsQuantum MechanicsQuantum NumbersQuantum NumbersQuantum Numbers (a closer look at shape)Quantum Numbers (a closer look at shape)Quantum Numbers (a closer look at shape)Quantum Numbers (a closer look at shape)Quantum NumbersQuantum Numbers (a closer look at Orientation)Quantum Numbersn and l for: Hydrogenn and l for: All other elementsn and l for: All other elementsQuantum NumbersPauli Exclusion PrincipleSample ProblemsSample ProblemsSample ProblemsSlide 41Sample ProblemsSample ProblemsSample ProblemsAssigning n & l ValuesClicker 6.6 – 6.8:Electron ConfigurationSample ProblemsSlide 49Clicker 6.12:Clicker 6.13:Clicker 6.14:Electron Configurations Cont’dSample ProblemsOrbital DiagramsSlide 56d-block Electron Configuration Exceptionsd-block Electron Configuration ExceptionsWhen are Elements Magnetic?Clicker 6.15:Valence ElectronsValence ElectronsAdded Info About Valence ElectronsClicker 6.17:Electron Configurations of IONSElectron Configurations of IONSSample Problem1Electronic Structureof AtomsChapter 6Chemistry the Central Scienceby: Brown, Lemay, Bursten, Murphy & WoodwardPresented by: Dr. Stacey GuldeWhy doesNeon Glow?Electrons excited to higher energies by electricityElectrons fall to a lower energy, emitting lightQuantum theory explains the behavior of electrons in atomsWill look at the arrangement of electrons in atoms (Aka: electronic structure of atoms)•Refers to the # of electrons in an atom AND their distribution around the nucleus23Dilemmas/Flaws of Atomic StructureFrom 1890 – 1930 a new theory developed a relationship b/t energy & particlesEnergy – ability to do work, to move matterUsually refer to matter in terms of an object (aka particle)Can also refer to matter in terms of radiation (aka energy)Scientist believed there was NO connection b/t the energy of particles & radiation, b/c of how then movedParticles move in straight linesRadiation moves in wavesWave PropertiesTerminology for discussing waves:Crest – highest point of waveWavelength,  (lamda) – distance b/t identical points•Unit = mFrequency,  (nu) – # of crests that pass a point in 1 sec•Unit = inverse time, s-1 (cycles per second): Hertz (Hz)4DistancecrestClicker 6.1:Which wave has the following?Longer wavelength Lower frequencyA. Red RedB. Red Blue C. Blue RedD. Blue BlueInverse relationship!Long  = Low 5Speed of WavesSpeed of wave – distance traveled per unit of timeSpeed of light (c) = 3.00x108 m/s (in vacuum)•inexact value = s-1 or Hz = m6c  cRadiation (aka Energy)Electromagnetic Spectrum – lists the different types ofradiation energyFamiliar with visible light•Eachcolor has adifferentENERGY7HighenergyLowenergyMax PlankMax Plank (1900) – figured out that energy and frequency are relatedRemember: So, 8E = energy of a quantum of light (J)h = Planck’s Constant (6.63 x 10-34 Js) = frequency (Hz or s-1)vhE chcE Sample ProblemGive the amount of energy associated with a radiation that has a wavelength of 575nm. What type of radiation is it?9=575nm  mElectro.SpectrumYellow lightE=?hcE nm575 nm1mx9101mx71075.5E sJx  341063.6 smx81000.3mx71075.5JxE191046.310What can we learn from White light?White light produces a Continuous spectrum – we see all colors (rainbow)Each color is a different energy, thus all energies possible11Atomic SpectraLight from a vaporized element, produces an Atomic spectrum – see some colorsOnly specific energies possibleColors given = Line spectrumEach element has a uniquespectrum (fingerprint)656nm486nm434nm410nmBohr Model ofHydrogen AtomNiels Bohr (worked w/Rutherford) suggested a model for existence of the hydrogen line spectrum1. H atom has certain allowable energy levels called stationary states, corresponding to a fixed electron orbit around the nucleus2. The atom doesn‘t give off energy while in a stationary state3. When an atom changes states, it experiences an overall energy equal to the difference between the 2 states1221 StateStateOverallEEE hQuantum StaircaseBohr attributed radiation emission (seeing light) to the dropping of an electron from a high energy state to a lowerGiving off a quantum of energy as lightTHERE IS A CONNECTION b/t PARTICLES & ENERGY!Quantum number, n (1, 2, 3…) = indicates the energy & radius of an electron orbitHigh n values: have high energy, thus a larger radius13Ground state (n = 1) – lowest energy of an electron•Most stable stateExcited state (n > 1) – higher energy level•Stability decreasesElectrons “jump” or leap from oneenergy state to anotherThey are never in-between themDirection matters:Promoting to higher n values: absorbs lightDropping to lower n values: gives off light14Quantum StaircaseBohrSpectral LinesMore energy is given off /absorbed when the dropping/promoting difference between energy levels (n) is large6  1 is larger than2  1 15Calculating Energyof ElectronsRydberg Equation: Calculates the amount (quanta) of energy to move from an initial to a final stateA negative E value indicates energy EMITTED,nfinal < ninitial16E = Energy (J)RH = Rydberg constant (2.18x10-18 J)n = energy levelhchE 2218111018.2initialfinalnnJxELimitations ofBohr’s Model1. Only works for hydrogen 2. Fails for atoms with more than 1 electronDue to:•Electron-electron: repulsions•Electron-nucleus: attractionsFor all other elements, we still use the terms ground/excided17Wave Behavior of MatterDeBroglie (1920’s) – suggested if light (energy) behaves like particles, then maybe particles (electrons) posses wave propertiesElectrons orbiting a nucleus must have a characteristic wavelength He dubbed the wave characteristic of particles: matter waves18Wave Behavior of MatterCombined