Honors Chemistry - CatalystHonors Chemistry - Catalyst Warm-up your AlgebraWarm-up your Algebra:: Use the Use the

equations given to solve for the equations given to solve for the following variables as stated: following variables as stated: c=c= ; ; E=hE=h

1.1. In the first equation, solve for In the first equation, solve for

2.2. Using both equations, solve for Using both equations, solve for EE using using hh, , cc, and , and

3.3. In the second equation, solve for In the second equation, solve for

Introduction to Quantum Introduction to Quantum Theory: History and WavesTheory: History and Waves

Honors ChemistryHonors ChemistryObj. #1-2Obj. #1-2

A brief history of quantum theoryA brief history of quantum theory

As you view the video clip record the As you view the video clip record the important contributions of each of the important contributions of each of the following peoplefollowing people– PlanckPlanck– EinsteinEinstein– BohrBohr– de Brogliede Broglie– HeisenbergHeisenberg

Part IPart I

Part IIPart II

Part IIIPart III

Wave-Particle DualityWave-Particle Duality

Einstein – 1905, Einstein – 1905, Wave-Wave-Particle DualityParticle Duality– ContinuousContinuous, like a , like a wavewave– Particle likeParticle like – a steady stream – a steady stream

of tiny bundles of energy called of tiny bundles of energy called photonsphotons that transmit a that transmit a discrete discrete quantity of energyquantity of energy

Photoelectric EffectPhotoelectric Effect: a : a photon of light must have a photon of light must have a certain threshold to free an certain threshold to free an electronelectron

Wave Particle DualityWave Particle Duality

Quantum modelQuantum model

•Electrons Electrons do do not orbitnot orbit the the nucleus.nucleus.

•Bohr’s model Bohr’s model only explained only explained HydrogenHydrogen

OrbitalOrbital

• OrbitalOrbital- a region in - a region in an atom where an atom where there is a high there is a high probability of probability of finding electrons.finding electrons.

Electromagnetic Radiation

Electric

Four Characteristics of Four Characteristics of WavesWaves

•AmplitudeAmplitude – height of a wave; – height of a wave; denotes intensity or brightnessdenotes intensity or brightness

•WavelengthWavelength – measured from crest – measured from crest to crest (in meters)to crest (in meters)

•c=c=λνλν, where c = speed of light and nu (, where c = speed of light and nu (νν) ) = cycles/second, Hertz, s= cycles/second, Hertz, s-1-1

•c = 3.00 x 10c = 3.00 x 1088 m/s m/s [Constant, always the [Constant, always the same]same]

Four Characteristics of Waves Four Characteristics of Waves (con’t)(con’t)

•Frequency (Frequency ())– how many – how many cycles pass a given point per cycles pass a given point per second (second (Hertz, Hz = sHertz, Hz = s-1-1))

- - E = hE = hνν, , where where h = Planck’s h = Planck’s constant 6.6262 x 10constant 6.6262 x 10-34-34 J·s J·s

•Speed (c)Speed (c) - speed of light, c, is - speed of light, c, is = 3.00 x 10= 3.00 x 1088 m/s m/s

Honors Chemistry Agenda – Honors Chemistry Agenda – 11/3/1111/3/11• CatalystCatalyst: Wave Equation Warm-up : Wave Equation Warm-up

& Review (half-sheet from by door)& Review (half-sheet from by door)

• NotesNotes: EMR spectrum and line : EMR spectrum and line emission spectraemission spectra

• ActivityActivity: View line emission spectra: View line emission spectra

• LabLab: Flame Test (complete and : Flame Test (complete and turn-in)turn-in)

• HomeworkHomework: Complete CALM T2, S1: Complete CALM T2, S1

Electromagnetic SpectrumElectromagnetic Spectrum

Continuous SpectrumContinuous Spectrum• Forms from the separation of white lightForms from the separation of white light• Consists of ROYGBIVConsists of ROYGBIV• Red – longest wavelengthRed – longest wavelength• Violet – shortest wavelengthViolet – shortest wavelength

Bright-line or Line-emission Bright-line or Line-emission SpectrumSpectrum• Consists of a few bands of colorConsists of a few bands of color

• ““finger-print” of an elementfinger-print” of an element

• First explained by Neils BohrFirst explained by Neils Bohr

Examples of Line spectraExamples of Line spectra

Neils Bohr - 1911Neils Bohr - 1911

• Used the line-emission spectrum for Used the line-emission spectrum for hydrogen to explain why electrons hydrogen to explain why electrons don’t collide into the nucleusdon’t collide into the nucleus

• Stated that electrons must be in Stated that electrons must be in distinct energy levels, ndistinct energy levels, n

• He called the lowest possible energy He called the lowest possible energy level the ground state. level the ground state.

Bohr (con’t)Bohr (con’t)

• Electrons can move to higher, or Electrons can move to higher, or excited states when they absorb excited states when they absorb energy.energy.

• When they return to their ground When they return to their ground state, they release that energy in the state, they release that energy in the form of ER, or light, with frequencies form of ER, or light, with frequencies that produced the line-emission that produced the line-emission spectrum.spectrum.

Bohr’s Model

Louis De Broglie - 1924Louis De Broglie - 1924

• Physics of the time could not apply to Physics of the time could not apply to particles like electronsparticles like electrons

• He described tiny particle behavior as He described tiny particle behavior as “matter waves”“matter waves”

= h/mv= h/mv; m=mass, v=velocity; m=mass, v=velocity

• All particles have these properties, All particles have these properties, but the more massive, the less but the more massive, the less noticeable.noticeable.

Louis De Broglie (con’t)Louis De Broglie (con’t)• Electrons exhibit standing-wave behaviorElectrons exhibit standing-wave behavior

Werner Heisenberg - 1927Werner Heisenberg - 1927Heisenberg’s Heisenberg’s

uncertainty uncertainty principle-principle- there is a there is a fundamental fundamental limitation to just limitation to just how precisely we how precisely we can know both the can know both the position and position and momentum of a momentum of a particle at a given particle at a given time. time.

Orbital TypesOrbital Types