CHEM: STRUC & PROP (LL) VOL 2 >C PKG<
2nd Edition
ISBN: 9780137390922
Author: Tro
Publisher: PEARSON C
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Textbook Question
Chapter 2, Problem 112E
Sunscreen contains compounds that absorb ultraviolet light. When sunscreen is applied to skin, it prevents ultraviolet light from reaching the skin. The graph that follows shows the absorbance of light as a function of wavelength for two different compounds (2-EHMC and TDSA) common in sunscreen. Absorbance is a measure of the amount of light absorbed by the compound-the higher the absorbance, the more light is absorbed. Study the graph and answer the question
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- Calculate the energy of a photon at the maximum absorption of TDSA.
- Calculate the energy of a photon at the maximum absorption of 2-EHMC.
- Which compound absorbs more energy at its maximum absorption?
- Why do you think sunscreens commonly contain both of these compounds and not just one of them?
- Assuming that sunlight produces 3.066 x 1022^ V ph°tQ1is, ^atthe skin absorbs one-half of these photons (and m2 • s reflects the other half), calculate the total UV energy absorbed over 0.42 m2 of skin that is exposed to sunlight for one hour. Assume that the average wavelength of the UV photons is 330 nm.
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Sunscreen contains compounds that absorb ultraviolet light. Whensunscreen is applied to skin, it prevents ultraviolet light from reachingthe skin. The graph that follows shows the absorbance of light as afunction of wavelength for two different compounds (2-EHMC andTDSA) common in sunscreen. Absorbance is a measure of theamount of light absorbed by the compound—the higher theabsorbance, the more light is absorbed. Study the graph and answerthe questions below.a. Calculate the energy of a photon at the maximumabsorption of TDSA.b. Calculate the energy of a photon at the maximum absorption of 2-EHMC.c. Which compound absorbs more energy at its maximum absorption?d. Why do you think sunscreens commonly contain both of these compounds and not just one of them?e. Assuming that sunlight produces 3.066 ? 1022 ?? ?ℎ??????2?and that the skin absorbs one-half of thesephotons (and reflects the other half), calculate the total UV energy absorbed over 0.42 m2of skin thatis exposed to sunlight for…
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a. Particles of light emit or absorb energy with surrounding molecules. This phenomenon is governed by the Law of Conservation of Energy.
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3. A prism is anle to differentiate the colors of the rainbow via refraction. The spectrometer uses a surface called a diffraction grating, which reflects light of various wavelengths at different angles. Give a real life example of an object or substance which acts as a diffracting grading, explain your reasoning.
Chapter 2 Solutions
CHEM: STRUC & PROP (LL) VOL 2 >C PKG<
Ch. 2 - Why is the quantum-mechanical model of the atom...Ch. 2 - What is light? How fast does it travel in a...Ch. 2 - Define the wavelength and amplitude of a wave.Ch. 2 - Define the frequency of electromagnetic radiation....Ch. 2 - What determines the color of light? Describe the...Ch. 2 - What determines the color of a colored object?...Ch. 2 - Give an approximate range of wavelengths for each...Ch. 2 - Explain the wave behavior known as interference....Ch. 2 - Explain the wave behavior known as diffraction....Ch. 2 - Describe the photoelectric effect. How did...
Ch. 2 - How did the photoelectric effect lead Einstein to...Ch. 2 - What is a photon? How is the energy of a photon...Ch. 2 - What is an emission spectrum? How does an emission...Ch. 2 - Describe the Bohr model for the atom. How did the...Ch. 2 - Explain electron diffraction.Ch. 2 - What is the de Broglie wavelength of an electron?...Ch. 2 - What are complementary properties? How does...Ch. 2 - Explain Heisenberg’s uncertainty principle. What...Ch. 2 - What is a trajectory? What kind of information do...Ch. 2 - Why does the uncertainty principle make it...Ch. 2 - Newton’s laws of motion are deterministic. Explain...Ch. 2 - An electron behaves in ways that are at least...Ch. 2 - What is a probability distribution map?Ch. 2 - For each solution to the Schrödinger equation,...Ch. 2 - What is a quantum-mechanical orbital?Ch. 2 - What is the Schrödinger equation? What is a wave...Ch. 2 - What are the possible values of the principal...Ch. 2 - What are the possible values of the angular...Ch. 2 - What are the possible values of the magnetic...Ch. 2 - Explain the difference between a plot showing the...Ch. 2 - Sketch the general shapes of the s, p, and d...Ch. 2 - List the four different sublevels. Given that only...Ch. 2 - Why are atoms usually portrayed as spheres when...Ch. 2 - The distance from the sun to Earth is 1.496108 km....Ch. 2 - The nearest star to our sun is Proxima Centauri,...Ch. 2 - List these types of electromagnetic radiation in...Ch. 2 - List these types of electromagnetic radiation in...Ch. 2 - Calculate the frequency of each wavelength of...Ch. 2 - Calculate the wavelength of each frequency of...Ch. 2 - Calculate the energy of a photon of...Ch. 2 - Calculate the energy of a photon of...Ch. 2 - A laser pulse with wavelength 532 nm contains 3.85...Ch. 2 - A heat lamp produces 32.8 watts of power at a...Ch. 2 - Determine the energy of 1 mol of photons for each...Ch. 2 - How much energy is contained in 1 mol of each?...Ch. 2 - Sketch the interference pattern that results from...Ch. 2 - What happens to the interference pattern described...Ch. 2 - The resolution limit of a microscope is roughly...Ch. 2 - The smallest atoms can themselves exhibit...Ch. 2 - What is the de Broglie wavelength of an electron...Ch. 2 - A proton in a linear accelerator has a de Broglie...Ch. 2 - Prob. 53ECh. 2 - A 0.22-caliber handgun fires a 27-g bullet at a...Ch. 2 - An electron has an uncertainty in its position of...Ch. 2 - An electron traveling at [1.35 \times {10^5}\] m/s...Ch. 2 - Which electron is, on average, closer to the...Ch. 2 - Which electron is, on average, further from the...Ch. 2 - What are the possible values of I for each given...Ch. 2 - What are the possible values of m1 for each given...Ch. 2 - Which set of quantum numbers cannot occur together...Ch. 2 - Which combinations of n and I represent real...Ch. 2 - Prob. 63ECh. 2 - Sketch the 3d orbitals. How do the 4d orbitals...Ch. 2 - An electron in a hydrogen atom is excited with...Ch. 2 - Determine whether each transition in the hydrogen...Ch. 2 - According to the quantum-mechanical model for the...Ch. 2 - According to the quantum-mechanical model for the...Ch. 2 - Calculate the wavelength of the light emitted when...Ch. 2 - Calculate the frequency of the light emitted when...Ch. 2 - Prob. 71ECh. 2 - An electron in a hydrogen atom relaxes to the [n =...Ch. 2 - Ultraviolet radiation and radiation of shorter...Ch. 2 - The human eye contains a molecule called...Ch. 2 - An argon ion laser puts out 5.0 W of continuous...Ch. 2 - A green leaf has a surface area of 2.50 cm2. If...Ch. 2 - Prob. 77ECh. 2 - An X-ray photon of wavelength 0.989 nm strikes a...Ch. 2 - Prob. 79ECh. 2 - The energy required to ionize sodium is 496...Ch. 2 - Prob. 81ECh. 2 - Suppose that, in an alternate universe, the...Ch. 2 - Prob. 83ECh. 2 - Prob. 84ECh. 2 - The binding energy of electrons in a metal is 193...Ch. 2 - In order for a thermonuclear fusion reaction of...Ch. 2 - Prob. 87ECh. 2 - Prob. 88ECh. 2 - The iodine molecule can be photodissociated...Ch. 2 - A sample of naphthalene in hexane contains 5.00104...Ch. 2 - Prob. 91ECh. 2 - Prob. 92ECh. 2 - Prob. 93ECh. 2 - The energy of a vibrating molecule is quantized...Ch. 2 - The wave functions for the 1s and 2s orbitals are...Ch. 2 - Before quantum mechanics was developed, Johannes...Ch. 2 - Find the velocity of an electron emitted by a...Ch. 2 - Water is exposed to infrared radiation of...Ch. 2 - Prob. 99ECh. 2 - A metal with a threshold frequency of 6.711014s1...Ch. 2 - Find the longest wavelength of a wave that can...Ch. 2 - The amount of heat to melt ice is 0.333 kJ/g. Find...Ch. 2 - Explain the difference between the Bohr model for...Ch. 2 - The light emitted from one of the following...Ch. 2 - Determine whether an interference pattern is...Ch. 2 - Which transition in the hydrogen atom results in...Ch. 2 - Discuss the nature of light with your group....Ch. 2 - How are electrons like baseballs? How are they...Ch. 2 - What are all the possible values of m1 if l = 0...Ch. 2 - Have each group member choose a set of quantum...Ch. 2 - How many nodes are there in the 1s, 2p, and 3d...Ch. 2 - Sunscreen contains compounds that absorb...Ch. 2 - Which wavelength of light has the highest...Ch. 2 - Which kind of electromagnetic radiation contains...Ch. 2 - How much energy (in J ) is contained in 1.00 mole...Ch. 2 - Light from three different lasers (A, B, and C),...Ch. 2 - Calculate the wavelength of an electron traveling...Ch. 2 - Which set of three quantum numbers does not...Ch. 2 - Calculate the wavelength of light emitted when an...Ch. 2 - Which electron transition produces light of the...Ch. 2 - How much time (in seconds) does it take light to...Ch. 2 - Which figure represents a d orbital? None of the...
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