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Explore the groundbreaking experiments of Planck and Einstein, including the Double Slit Experiment and the UV catastrophe, that provided proof of light's dual nature as both a particle and a wave.
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The Big Picture (from yesterday) (Planck and Einstein) (Planck) Light is a… (Maxwell) Particle Wave Proof: Proof: Double Slit Experiment (Young) U.V. catastrophe and the photo-elelctric effect Parameters: Parameters: m, E, h l, n, c
The Bohr Model… a review Shells Bohr suggested that electrons existed in _______ surrounding the nucleus. The shell closest to the nucleus represented the ________amount of energy… ---therefore, shells further away __________________________________ ---in an energy level, the electron can neither ____________________ The electron can ______ to the next energy level (or levels further away if it receives _________________________________ ---the lowest energy level is called: _____________ ---other than the lowest energy level is called: ___________________ When electrons move from higher to lower energy levels _______________________________ Do you recognize a significant term which might describe this energy release? _________________ -There are only certain distances allowable -Distances are analogous to the energy the electron possesses. (called energy levels) Lowest Possess greater amounts of energy Lose nor gain energy jump The exact amount of energy needed The ground state An excited state. Release specific amounts of energy A quantum or photon
The Bohr Equation: Charge on electron ▼ Mass of electron ▼ -Z2e4me En= 8eo2n2h2 Planck’s ◄Constant ▲ Permittivity of a vacuum: relates to a material's ability to transmit (or "permit") an electric field. -RZ2 En= n2 Rydberg Constant -2.178 x 10-18 J Z2 En= n2
The Bohr Equation: En = -2.178 x 10-18 J (Z2/n2) Directions: find the energies associated with the first 7 electron energy levels in the hydrogen atom. Write the values on the appropriate line. What would be the value for the energy of the infinite energy level (i.e. n = ∞ )? For n= ∞ E = 0 J For n= 7 E = -4.445 x 10-20 J For n= 6 E = -6.050 x 10-20 J For n= 5 E = -8.712 x 10-20 J For n= 4 E = -1.361 x 10-19 J For n= 3 E = -2.420 x 10-19 J For n= 2 E = -5.445 x 10-19 J For n= 1 E = -2.178 x 10-18 J Nucleus
DE =-5.445 x 10-19J – ( -2.420 x 10-19 J) DE = -3.025 x 10-19J ( a photon of light released) E =hn ; n = E/h n = 4.6 x 1014/s l x n = c ; l = c/nl = 6.6 x 10-7 m Find the amount of energy associated with an electron jumping from energy level 3 to energy level 2. What would be the frequency of that photon What would be the wavelength of that photon For n= ∞ E = 0 J For n= 7 E = -4.445 x 10-20 J For n= 6 E = -6.050 x 10-20 J For n= 5 E = -8.712 x 10-20 J For n= 4 E = -1.361 x 10-19 J For n= 3 E = -2.420 x 10-19 J For n= 2 E = -5.445 x 10-19 J For n= 1 E = -2.178 x 10-18 J Nucleus