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Ch.5 - Periodicity & Electronic Structure of Atoms
Chapter 5, Problem 45

What is the energy of each of the following photons in kilojoules per mole? (a) v = 5.97 * 1019 s-1 (b) v = 1.26 * 106 s-1 (c) = 2.57 * 102 m

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Photon Energy

Photon energy is the energy carried by a single photon, which can be calculated using the equation E = hν, where E is energy, h is Planck's constant (6.626 x 10^-34 J·s), and ν (nu) is the frequency of the photon in hertz. This relationship shows that higher frequency photons have greater energy.
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Planck's Constant

Planck's constant is a fundamental constant in quantum mechanics that relates the energy of a photon to its frequency. It is a key component in the equation E = hν, and its value is approximately 6.626 x 10^-34 J·s. Understanding this constant is essential for calculating photon energies.
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Conversion to Kilojoules per Mole

To express the energy of photons in kilojoules per mole, one must convert the energy from joules to kilojoules and then multiply by Avogadro's number (approximately 6.022 x 10^23 mol^-1). This conversion is necessary because the question asks for energy on a per mole basis, which is a common unit in chemistry.
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