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Ch.5 - Periodicity & Electronic Structure of Atoms

Chapter 5, Problem 54

The work function of silver metal is 436 kJ/mol. What frequency of light is needed to eject electrons from a sample of silver?

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hey everyone in this example, we need to calculate the frequency threshold for the emission of electrons in iron. If the energy threshold via the photo electric effect is equivalent to this value given. So we're going to recall our formula for the energy of a photon, which we would recall is equal to Plank's constant, multiplied by our frequency. So because the prompt is asking for frequency, we're going to find frequency by isolating it from plank's constant so that we now have energy of our photon divided by Plank's constant. So to find frequency, we would say that it's equal to murder our energy threshold given in the prompt is 6.878 times 10 to the negative 19th power jewels. And in our denominator we would recall that Plank's constant is 6. times 10 to the negative 34th power units of jewels, times seconds. We're going to be able to cancel out jewels leaving us with inverse seconds as our final unit for frequency which is the proper unit. And we're going to get that our frequency is equal to a value of 1.03, 8 Times 10 to the 15th power inverse seconds. And so this will be our final answer. To complete this example as the frequency threshold for the emission of our electrons in our atoms of iron. If you have any questions, please leave them down below. Otherwise, I'll see everyone in the next practice video
Related Practice
Textbook Question
(c) What is the color of the light with = 450 nm?
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Textbook Question
The work function of cesium metal is 188 kJ/mol, which corresponds to light with a wavelength of 637 nm. Which of the following will cause the smallest number of electrons to be ejected from cesium? (a) High-amplitude wave with a wavelength of 500 nm (b) Low-amplitude wave with a wavelength of 500 nm (c) High-amplitude wave with a wavelength of 650 nm (d) Low-amplitude wave with a wavelength of 650 nm
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Textbook Question
The work function of calcium metal is kJ/mol, which corresponds to light with a wavelength of 432 nm. Which of the following will cause the largest number of electrons to be ejected from cesium? (a) High-amplitude wave with a wavelength of 400 nm (b) Low-amplitude wave with a wavelength of 400 nm (c) High-amplitude wave with a wavelength of 450 nm (d) Low-amplitude wave with a wavelength of 450 nm
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Textbook Question
Cesium metal is frequently used in photoelectric cells because the amount of energy necessary to eject electrons from a cesium surface is relatively small—only 206.5 kJ/mol. What wavelength of light in nanometers does this correspond to?
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Textbook Question
Spectroscopy is a technique that uses the interaction of radiant energy with matter to identify or quantify a substance in a sample. A deuterium lamp is often used a light source in the ultraviolet region of the spectrum and the emission spectrum is shown. Is this a continuous or line emission spectrum?

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Textbook Question
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