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Ch.5 - Periodicity & Electronic Structure of Atoms
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All textbooksMcMurry 8th EditionCh.5 - Periodicity & Electronic Structure of AtomsProblem 136a

Chapter 5, Problem 136a

A minimum energy of 7.21⨉10-19 J is required to produce the photoelectric effect in chromium metal. (a) What is the minimum frequency of light needed to remove an electron from chromium?

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Hello everyone today. We have the following problem. If at least 3.94 times 10 to the negative 18 jewels of energy is required to induce the photo electric effect. What is the lowest light frequency required to eject an electron from a pure metal sample? So from this, it's important to recall at a very important equation known as Plank's equation. And Plank's equation says that the energy of a photon is equal to Planck's constant times the frequency. And so essentially we want to solve for the frequency. So we have to rearrange this equation so that we get the frequency is equal to the energy of the photon over Plank's constant. And so we simply have to plug in our values to solve our frequency. So the energy of the photon is 3.94 times 10 to the negative 18th jewels And Planck's constant is going to be 6.6-6 Times 10 to the negative 34 jules, times seconds. When our units of jewels cancel out, we will be left with a frequency of 5.95 times to the 15th seconds to the negative first power since seconds was in the denominator in the equation. And so this is going to be the lowest frequency required to eject an electron from a pure metal sample overall, I hope that this helped. And until next time
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Textbook Question
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In the Bohr model of atomic structure, electrons are constrained to orbit a nucleus at specific distances, given by the equation

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Assume that the rules for quantum numbers are different and that the spin quantum number ms can have any of three values, ms = -1/2, 0, +1/2, while all other rules remain the same. (a) Draw an orbital-filling diagram for the element with Z = 25, showing the individual electrons in the outer-most subshell as up arrows, down arrows, or 0. How many partially filled orbitals does the element have?
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Textbook Question

A minimum energy of 7.21⨉10-19 J is required to produce the photoelectric effect in chromium metal. (b) Light with a wavelength of 2.50⨉10-7 m falls on a piece of chromium in an evacuated glass tube. What is the minimum de Broglie wavelength of the emitted electrons? (Note that the energy of the incident light must be conserved; that is, the photon's energy must equal the sum of the energy needed to eject the electron plus the kinetic energy of the electron.)

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Textbook Question
(c) What is the velocity of an electron with a de Broglie wavelength equal to (b)?
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An energetically excited hydrogen atom has its electron in a 5f subshell. The electron drops down to the 3d subshell, releasing a photon in the process. (b) What wavelength of light is emitted by the process?

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