Match the description of a process with the corresponding arrow in figure 8.38: (a) Absorption of a photon whose energy is E1-E0. (b) Absorption from an excited state (a rare event at ordinary temperatures). (c) Emission of a photon whose energy isE3-E1 . (d) Emission of a photon whose energy isE2-E0 . (e) In drawing arrows to represent energy transitions, which of the following statement are correct. (1) it doesn’t matter in which direction you draw the arrow as long as it connects the initial and final states. (2) For emission, the arrow points down. (3) For absorption, the arrow points up. (4) The tail of the arrow is drawn on the initial state. (5) The head of the arrow is drawn on the final state. (6) It is not necessary to draw and arrowhead.

Short Answer

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Solution of the given question is shown in the below step in detail explanation.

Step by step solution

01

Concept Introduction

Whenever the bright lines fall on the metal surface, the emission of a photon takes place, and when the dark lines fall on the metal surface, the absorption of a photon takes place.

02

Explanation for (a)

Given that the photon is getting absorbed with the energy of E1E0.

For the absorption process the tail of the arrow should be in the initial state and the head of the arrow should be in the final state. As here energy is E1E0, so the tail of the arrow should be at E0 and the head of the arrow should be at E1.

Therefore absorption of photon whose energy isE1E0 is represented by arrow 1.

03

Explanation for (b)

Given that absorption of photon takes place from an excited state (a rare event at low temperatures).

In the given diagram absorption of photon takes place from the excited state E1to E3.

Therefore the absorption from the excited state ( a rare event at low temperature) is represented by arrow .

04

Explanation for (c)

Given that the photon is getting emitted with the energy of E3E1.

For the emission process the tail of the arrow should be in the initial state and the head of the arrow should be in the final state. As here energy is E3E1, so the tail of the arrow should be at E3and the head of the arrow should be at E1.

Therefore, emission of photon whose energy is E3E1is represented by arrow 2.

05

Explanation for (d)

Given that the photon is getting emitted with the energy of E2E0.

For the emission process the tail of the arrow should be in the initial state and the head of the arrow should be in the final state. As here energy is E2E0, so the tail of the arrow should be at E2 and the head of the arrow should be at E0.

Therefore emission of photon whose energy is E2E0 is represented by arrow 3.

06

Explanation for  (e)

  1. In case of the absorption, the head of the arrow points up, whereas in case of emission the head of the arrow pints down. So the given statement is false.
  2. In case of emission the head of the arrow pints down. So the given statement is true.
  3. In case of the absorption, the head of the arrow points up. So the given statement is true.
  4. For the emission process the tail of the arrow should be in the initial state. So the given statement is true.
  5. For the emission or absorption, the head of the drawn to the final state. So the given statement is true.
  6. For the emission or absorption, the head of the drawn to the final state. If there is no error, so we can’t be able to find whether the transition is emission or absorption. So the given statement is false.

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Most popular questions from this chapter

Consider a microscopic spring–mass system whose spring stiffness is50N/m, and the mass is4×10-26kg. (a) What is the smallest amount of vibrational energy that can be added to this system? (b) What is the difference in mass (if any) of the microscopic oscillator between being in the ground state and being in the first excited state? (c) In a collection of these microscopic oscillators, the temperature is high enough that the ground state and the first three excited states are occupied. What are possible energies of photons emitted by these oscillators?

Energy graphs: (a) Figure 8.41 shows a graph of potential energy vs. interatomic distance for a particular molecule. What is the direction of the associated force at location A? At location B? At location C? Rank the magnitude of the force at locations A,B and C. (That is, which is greatest , which is smallest, and are any of these equal to each other?) For the energy level shown on the graph, draw a line whose height is the kinetic energy when the system is at location D.

(b) Figure 8.42 shows all of the quantized energies (bound states) for one of these molecules. The energy for each state is given on the graph, in electron volts ( 1eV=1.6×1019J). How much energy is required to break a molecule apart, if it is initially in the ground state? (Note that the final state must be an unbound state; the unbound states are not quantized.)

(c) At high enough temperatures, in a collection of these molecules there will be at all times some molecules in each of these states, and light will be emitted. What are the energies in electron volts of the emitted light?

(d) The "inertial" mass of the molecule is the mass that appears in Newton's second law, and it determines how much acceleration will result from applying a given force. Compare the inertial mass of a molecule in the ground state and the inertial mass of a molecule in an excited state10eV above the ground state. If there is a difference, briefly explain why and calculate the difference. If there isn't a difference, briefly explain why not.)

If you try to increase the energy of a quantum harmonics oscillator by adding an amount of energy 12hks/m, the energy doesn’t increase. Why not?

Suppose we have a reason to suspect that a certain quantum object has only three quantum states.When we excite a collection of such objects we observe that they emit electromagnetic radiation of three different energies: 0.3eV(infrared), 2.0eV(visible), and 2.3eV(visible).

(a) Draw a possible energy-level diagram for one of the quantum objects, which has three bound states. On the diagram, indicate the transitions corresponding to the emitted photons, and check that the possible transitions produce the observed photons and no others. The energyK+U of the ground state is -4eV. Label the energies of each level ( K+U, which is negative).

(b) The material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. Next a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. What photon energies in this beam of light are observed to be significantly reduced in intensity ("dark absorption lines")? Energy of highest-energy dark line: eV Energy of lowest-energy dark line: eV

(c) There exists another possible set of energy levels for these objects which produces the same photon emission spectrum. On an alternative energy-level diagram, different from the one you drew in part (a), indicate the transitions corresponding to the emitted photons, and check that the possible transitions produce the observed photons and no others. When you are sure that your alternative energy-level diagram is consistent with the observed photon energies, enter the energies of each level (K+U, which is negative).

(d) For your second proposed energy-level scheme, what photon energies would be observed to be significantly reduced in intensity in an absorption experiment ("dark absorption lines")? (Given the differences from part (b), you can see that an absorption measurement can be used to tell which of your two energy-level schemes is correct).

Suppose we have reason to suspect that a certain quantum object has only three quantum states. When we excite such an object we observe that it emits electromagnetic radiation of three different energies: 2.48eV(green), 1.91eV(orange), and 0.57eV(infrared). (a) Propose two possible energy-level schemes for this system. (b) Explain how to use an absorption measurement to distinguish between the two proposed schemes.

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