Ch.7 - Quantum MechanicsWorksheetSee all chapters
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Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Electrons can move up and down to different orbitals or shells based on absorbing or releasing of energy. 

Bohr's Model of the Atom

Concept #1: Understanding the Atom

Transcript

In this new video, we're going to continue with the discussion of the atomic model. We're going to say an atom is composed of three subatomic particles. On our right side, we have a picture of our atom. Remember, in the center of an atom is where we find the nucleus. This right here represents our nucleus. Now it's not drawn exactly to scale. Remember the nucleus contains the majority of the mass of an atom, but the nucleus itself is very small compared to the rest of the atom.
We're going to say that the nucleus, being in the center, contains two of the three subatomic particles. It contains the protons and the neutrons. We're going to say spinning around our nucleus we find the third subatomic particle, our electrons. Remember that the protons are positively charged, remember that the electrons are negatively charged and remember that the neutrons have no charge, so non-charged subatomic particles.
Because the nucleus is composed of protons which are positive and neutrons which are neutral, the nucleus itself is positively charged. We're going to say that, we're going to cancel out those positive charges by the electrons that spin around the nucleus, so that's why an atom is a neutral species. 

Bohr's Model tries to explain what happens to the electron when it absorbs or emits energy. 

Concept #2: Absorption vs. Emission

Transcript

We've learned all these things before. Here's what we come up with new understandings of the atom and how the electrons work within it. Now, we're going to say according to Bohr's model, it helps explain what happens when electron absorbed or released energy within a hydrogen atom.
What we're going to say here is, this blue right here represents our nucleus, where we find our protons and our neutrons. And here we’re going to say that this first circle here represents our first shell. In our first shell, we have an electron. That electron is going to absorb light energy from a photon. When that electron absorbs this energy, it becomes excited.
So that's what we're going to put down here. We're going to say, when it absorbs enough energy, it becomes excited. Once it becomes excited, it's able to jump from the first shell or whatever shell it's into a higher leveled shell. The electron absorbs energy and it jumps up to here, so that's why we find it in the second shell.
The thing is, electrons that absorb energy, they can't hold on to the energy forever. Eventually, they're going to release this energy slowly back from where it came. So the electron is slowly going to release this energy and this energy is going to be emitted as heat or light and when it's releasing this energy back from where it came, it's going to come and return back to what we call its ground-state level. Ground state level just means that it returns to the level it was at before it absorbed that energy.
What we should see to the right of this -- so we've already talked about what happens when it absorbs energy—it jumps up to a higher level. When it releases energy it falls back down to its previous level.
Here on the right side, we have a diagram. Now, this diagram basically shows us how much energy is required when we go from one shell to the next shell. As you can see here, this represents shell number one, shell number two, three, four, infinity, and we're going to say that in this model, distance equals energy.
So you can see that going from shell one to shell two is the biggest difference, the biggest distance involved. Because of that, we're going to say going from one to two or two to one involves the most amount of energy, because we said that the distance equals energy. You’re also going to notice as we go from two to three, the distance gets a lot smaller, so we're going to say going between two and three requires less energy. As we go from three to four, it gets even smaller.
You can see in the pattern if we're trying to go from level four to five, it'd be even smaller still and going from six to seven—it will be almost like doing nothing. You'd be able to just step over into the next shell. So we're going to say the higher up you go in shell number, the smaller the distance is and the less energy is required of us to go from one to the other.
Just remember this, the lowered number shells, there's bigger difference in distance between them and because of that, it takes more energy. So it takes more energy to go from one to two than it does to go from three to four.
Just remember when we talk about absorption, we're having the electron go from a certain level up to a higher numbered level. When it releases or what we say emits this absorbed energy, it's going to fall back down. It's going to go from a larger number, back down to a smaller number.
Just remember these concepts, what's the difference between absorption and emission and remember distance equals energy in terms of the electron going from one shell to the next shell.

In absorption, an electron gains energy and becomes excited. In this excited state, the electron moves to higher energy level. 

In emission, the electron releases its excess energy to go down to a lower energy level.

Example #1: Calculate the energy of the 4th electron found in the n = 2 state of the boron atom in kilojoules per mole. 

Practice: Which of the following transitions (in a hydrogen atom) represents emission of the longest wavelength?

Practice: Which of the following transitions represents absorption of a photon with the largest energy?    

Atomic Emission

Concept #3: Understanding Absorption & Emission

Transcript

In this new video, we're going to take a look at atomic emission. Now, we'd say that when electrons absorbs enough energy, it's going to go from a smaller numbered shell and it's going to use that energy to push itself up to a higher numbered shell. So example, it's going to go from shell number two up to shell number four, and we use n to represent that shell number.
Now, in the opposite way, that electron eventually can release or emit the energy that it absorbed and when it does this, it goes from the higher numbered shell to the lowered numbered shell. It goes back to where it came.
Remember the difference between absorption where we're taking energy in and using that energy to jump up to a higher level. Releasing or emitting means that we're releasing that energy that we absorb. When we release that energy, we fall back down to what we call our ground state, our normal energy level. 

Concept #4: Different Emission Series

Transcript

Now, we're going to say, depending on which level we rest back on, we have different types of emission series. Now, we're going to say, if the electron goes from a higher numbered shell to the first shell, it's referred to as a Lyman series. Here we have the sign infinity, meaning that we could start from any shell, shell two to shell seven, it doesn't matter, as long as we wind up going back down to shell number one, it's going to be a Lyman series.
We're going to say if the electron goes from a higher numbered shell to the second shell, it's no longer called the Lyman series—it's going to be called a Balmer series. Again, any number higher than two, three to seven, if we start at any one of those levels and come back down and rest at level two, shell two, then it's a Balmer series.
Then, we're going to say if the electron goes from a higher numbered shell, if it starts from the third shell -- higher numbered shell then goes down to the third shell, then it’s going to be called a Paschen Series. So we're going to start out at levels higher than three, so from four to seven. You start at shell six you can go down to three.
Just remember, remember the difference between absorption versus emission. Remember, we have different types of emission series, depending on what level we fall back down to, whether it will be level one shell one, shell two or shell three. They each have different names to them and they all have different energies. Because remember, we're releasing energy, depending on where you fall, you're releasing different quantities of energy. 

We know that emission is the releasing of energy, but different energies are released depending on which shell the electron falls. These different energies appear in different places on the electromagnetic spectrum. 

Example #2: What is the wavelength of a photon (in nanometers) emitted during a transition from n = 4 to n = 2 state in the hydrogen atom?

Practice: Classify each of the following transitions as either a Lyman, Balmer or Paschen series. a) n = 3 to n = 1 b) n = 6 to n = 1 c) n = 3 to n = 2 d) n = 6 to n = 3 e) n = 4 to n = 2

Change in energy states for absorption and emission.Which transition will lead to the emission of light with longer wavelength?
Color and temperature. The color and intensity of the light emitted by a hot object, such as this nail, depend on the temperature of the object.Which is at a higher temperature: the part of the nail glowing yellow or the part glowing red?
Stars do not all have the same temperature. The color of light emitted by stars is characteristic of the light emitted by hot objects. Telescopic photos of three stars are shown below: (i) the Sun, which is classified as a yellow star, (ii) Rigel, in the constellation Orion, which is classified as a blue-white star, and (iii) Betelgeuse, also in Orion, which is classified as a red star.Place these three stars in order of increasing temperature.
True or False: There is an upper limit on the energy of a photon that can be emitted from a hydrogen atom.
How does an emission spectrum of a gas in a discharge tube differ from a white light spectrum?
Is energy emitted or absorbed when the following electronic transitions occur in hydrogen?from n = 4 to n = 2,
One of the emission lines of the hydrogen atom has a wavelength of 93.07 nm.Determine the initial value of n associated with this emission.
One of the emission lines of the hydrogen atom has a wavelength of 93.07 nm.Determine the final value of n associated with this emission.
If you put 120 volts of electricity through a pickle, the pickle will smoke and start glowing orange-yellow. The light is emitted because sodium ions in the pickle become excited; their return to the ground state results in light emission.If you soaked the pickle for a long time in a different salt solution, such as strontium chloride, would you still observe 589-nm light emission?
Certain elements emit light of a specific wavelength when they are burned. Historically, chemists used such emission wavelengths to determine whether specific elements were present in a sample. Some characteristic wavelengths for some of the elements are Ag 328.1 nm Fe 372.0 nm Au 267.6 nm K 404.7 nm Ba 455.4 nm Mg 285.2 nm Ca 422.7 nm Na 589.6 nm Cu 324.8 nm Ni 341.5 nm Determine which elements emit radiation in the visible part of the spectrum.
Certain elements emit light of a specific wavelength when they are burned. Historically, chemists used such emission wavelengths to determine whether specific elements were present in a sample. Some characteristic wavelengths for some of the elements are Ag 328.1 nm Fe 372.0 nm Au 267.6 nm K 404.7 nm Ba 455.4 nm Mg 285.2 nm Ca 422.7 nm Na 589.6 nm Cu 324.8 nm Ni 341.5 nm Which element emits photons of lowest energy?
Place the following transitions of the hydrogen atom in order from longest to shortest wavelength of the photon emitted.
The series of emission lines of the hydrogen atom for which nf = 3 is called the Paschen series.Calculate the wavelengths of the first three lines in the Paschen series-those for which ni =4, 5 and 6.
Order the following transitions in the hydrogen atom from largest to smallest frequency of light absorbed.
When the spectrum of light from the Sun is examined in high resolution in an experiment similar to that illustrated in Figure 6.11 in the textbook, dark lines are evident. These are called Fraunhofer lines, after the scientist who studied them extensively in the early nineteenth century. Altogether, about 25,000 lines have been identified in the solar spectrum between 2950 Å and 10,000 Å. The Fraunhofer lines are attributed to absorption of certain wavelengths of the Suns "white" light by gaseous elements in the Suns atmosphere.Describe the process that causes absorption of specific wavelengths of light from the solar spectrum.
Is energy emitted or absorbed when the following electronic transitions occur in hydrogen: (a) from n = 4 to n = 2
Which electronic transition in atomic hydrogen corresponds to the emission of visible light?a) n = 5 → n = 2b) n = 1 → n = 2c) n = 3 → n = 4d) n = 3 → n = 1 
Indicate whether energy is emitted or absorbed when the following electronic transitions occur in hydrogen: (a) from n = 2 to n = 6
Consider the process of 2 H(g) → H2(g) where ΔH = −436 kJ/molDetermine if the sentence below is true or false.Shining light on hydrogen atoms could put electrons in  n = 3, provided the intensity was sufficiently high.
How many unique emission lines are observed from a system with four equally spaced energy levels?a. 1b. 2c. 3d. 4e. 5
The lines in an atomic absorption spectrum are due to1. the presence of isotopes.2. movement of electrons from higher energy states to lower energy states in atoms.3. nuclear transitions in atoms.4. movement of electrons from lower energy states to higher energy states in atoms. 
Using the figure down below, complete the following statement: When an electron undergoes Transition A, it ________ energy, and when it undergoes Transition B, it ________ energy and __________. A. absorbs, emits, absorbs electromagnetic radiationB. absorbs, releases, absorbs electromagnetic radiationC. absorbs, releases, emits electromagnetic radiationD. releases, absorbs, absorbs electromagnetic radiationE. releases, absorbs, emits electromagnetic radiation
One of the emission lines of the hydrogen atom has a wavelength of 93.8 nm. (a) In what region of the electromagnetic spectrum is this emission found?
Which of the following statements is/are true?a. An emission spectrum is formed when a beam of white light passes through a sample of gasb. An emission spectrum is formed by an electric current passing through a gas in a vacuum tubec. The photoelectric effect is due to particle-like behavior of lightd. The photoelectric effect is due to wave behavior of light1. A & C2. B & D3. A & D4. B & C5. C & D
For a hydrogen atom, which case will result in an absorption spectrum with the highest frequency?a.  an electron transition from n = 1 → n = 2b.  an electron transitions from n = 1 → n = 4c.  an electron transition from n = 2 → n = 3d.  an electron transitions from n = 3 → n = 1e.  an electron transition from n = 4 → n = 3
Which of the following statements is (are) TRUE?I. An excited atom can return to its ground state by absorbing electromagnetic radiation.II. The energy of an atom is increased when electromagnetic radiation is emitted from it.III. The energy of electromagnetic radiation increases as its frequency increases.IV. An electron in the n = 4 state in the hydrogen atom can go to the n = 2 state by emitting electromagnetic radiation at the appropriate frequency.V. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other.  a)   II, III, IV,b)   III, Vc)   I, II, IIId)   III, IV, Ve)   I, II, IV
Complete this sentence: Atoms emit visible and ultraviolet light a. as electrons jump from lower energy levels to higher levels. b. as the atoms condense from a gas to a liquid. c. as electrons jump from higher energy levels to lower levels. d. as they are heated and the solid melts to form a liquid. e. as the electrons move about the atom within an orbit.
The lines in the emission spectrum of hydrogen result from __________. A) electrons given off by hydrogen as it coolsB) decomposing hydrogen atomsC) electrons given off by hydrogen when it burnsD) energy given off in the form of visible light when an electron moves from a higher energy state to a lower energy stateE) protons given off when hydrogen burns
The lines in the emission spectrum of hydrogen result from ___________________ .A) electrons given off by hydrogen as it coolsB) decomposing hydrogen atomsC) electrons given off by hydrogen when it burnsD) energy given off in the form of visible light when an electron moves from a higher energy state to a lower energy stateE) protons given off when hydrogen burns
The lines in an atomic absorption spectrum are due to1. the presence of isotopes.2. movement of electrons from higher energy states to lower energy states in atoms.3. nuclear transitions in atoms4. movement of electrons from lower energy states to higher energy states in atoms.
According to the Bohr model for the hydrogen atom, which of the following transitions will emit light with the longest wavelength?a. from the n = 4 to n = 2 energy level.b. from the n = 4 to n = 3 energy level.c. from the n = 3 to n = 1 energy level.d. from the n = 6 to n = 2 energy level.e. from the n = 5 to n = 3 energy level.
Which emission line in the hydrogen spectrum occurs at the highest frequency?a) n = 3 → n = 1b) n = 4 → n = 2c) n = 7 → n = 5d) n = 10 → n = 8
Which of the following processes is endothermic?a. An atom emits a photon.b. The electron gain process of a fluorine atom.c. An atom absorbs a photon.d. The condensation of water.e. None of the above processes are endothermic.
Which of the following transitions (in a hydrogen atom) represent  emission of the smallest or shortest wavelength? n = 4 to n = 2n = 3 to n=  4n = 1 to n = 2n = 7 to n = 5n = 2 to n = 5
Which of the following emission lines corresponds to part of the Balmer series of lines in the spectrum of a hydrogen atom?A) n2 → n1B) n4 → n2C) n4 → n1D) n3 → n2E) n4 → n3 1. B and D only2. E only3. A and C only4. A, D, and E only5. B and C only 
Which of the following statements is or are true?1. An excited atom can return to a lower energy level by absorbing light energy.2. An atom can be excited by emitting light energy.3. As the energy of electromagnetic radiation increases, its frequency increases.4. The frequency and wavelength of light are inversely proportional.a) 1 and 2 onlyb) 2 onlyc) 2 and 3d) 1 and 3e) 3 and 4
According to the Bohr model for the hydrogen atom, the energy necessary to excite an electron from n = 1 to n = 2 is _______ the energy necessary to excite an electron from n = 5 to n = 6. equal to either less or equal to greater than less than either equal to or greater than
According to the quantum-mechanical model for the hydrogen atom, which electron transition would produce light with the longest wavelength?4p → 3p 4s → 3p 5s → 4p 3p → 2a 2p → 1s
According to the Bohr atomic theory, when an electron moves from one energy level to another further from the nucleusa) energy has been absorbedb) energy has been emittedc) light has been emittedd) photons have been dischargede) no change in energy is observed
Atoms emit visible, IR, and UV light _____________ a) as electrons jump from lower energy levels to higher levels.b) as electrons drop from higher energy levels to lower levels.c) As they are heated and the solid melts to form a liquid.d) As the atoms condense from a gas to a liquid.e) As the electrons move about the atom within an orbit.  The order of the lower energy levels for the question above area) 1, 2, 3b) 3, 2, 1c) 2, 3, 1d) 2, 1, 3e) 1, 3, 2
Which electron transition produces light of the highest frequency in the hydrogen atom?a) 5p → 1sb) 4p → 1sc) 3p → 1sd) 2p → 1s
If the transition of an electron from the n = 3 state to the n = 2 state results in emission of visible light, is the transition from the n = 2 state to the n = 1 state more likely to result in the emission of infrared or ultraviolet radiation?
Why is it necessary to use the Kα transition (2s → 1p) in copper to generate X-rays? Why not use, for example, the (4p → 3s) transition?
Five lines in the H atom spectrum have these wavelengths (in Å): (a) 1212.7; (b) 4340.5; (c) 4861.3; (d) 6562.8; (e) 10,938. Three lines result from transitions to nfinal = 2 (visible series). The other two result from transitions in different series, one with nfinal = 1 and the other with nfinal = 3. Identify n initial for each line.
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Three electromagnetic waves, all drawn on the same scale, are also shown. Each corresponds to one of the transitions. Which electromagnetic wave--(i), (ii), or (iii)--is associated with electronic transition A?
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the energy of the photon emitted for transition A.
Which transition emits light with the shortest wavelength?(a) n = 5 → n = 4(b) n = 4 → n = 3(c) n = 3 → n = 2
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the energy of the photon emitted for transition B  .
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the energy of the photon emitted for transition C  .
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the wavelength of the photon emitted for transition A.
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the wavelength of the photon emitted for transition B  .
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Calculate the wavelength of the photon emitted for transition C  .
Consider the three electronic transitions in a hydrogen atom shown here, labeled A, B, and C.Do any of these transitions lead to the emission of visible light? If so, which one(s)?
According to the quantum-mechanical model for the hydrogen atom, which electron transitions produces light with the longer wavelength: 2p → 1s or 3p → 1s?
According to the quantum-mechanical model for the hydrogen atom, which electron transitions produces light with the longer wavelength: 3p → 2s or 4p → 3p?
Which transition in the hydrogen atom produces emitted light with the longest wavelength?a. n = 4 → n = 3b. n = 2 → n = 1c. n = 3 → n = 2
Lines in one spectral series can overlap lines in another.  Does the range of wavelengths in the  n1 = 1 series for the H atom overlap the range in the  n1 = 2 series?
Lines in one spectral series can overlap lines in another.  Does the range in the  n1 = 3 series overlap the range in the  n1 = 4 series?
Lines in one spectral series can overlap lines in another. How many lines in the  n1 = 4 series lie in the range of the  n1 = 5 series?
Lines in one spectral series can overlap lines in another. What does this overlap imply about the H atom line spectrum at longer wavelengths?
What is the wavelength (in nm) of the least energetic spectral line in the infrared series of the H atom?
An electron in a hydrogen atom is excited with electrical energy to an excited state with n = 2. The atom then emits a photon. What is the value of n for the electron following the emission?
A Bohr-model representation of the H atom is shown below with several electron transitions depicted by arrows:Rank the emissions in terms of increasing energy.
The flame tests for sodium and potassium are based on the emissions at 589 nm and 404 nm, respectively. When both elements are present, the Na+ emission is so strong that the K + emission can be seen only by looking through a cobalt-glass filter. Why is KClO4 used as an oxidizing agent in fireworks rather than NaClO4?
Assume that a hydrogen atom’s electron has been excited to the n = 5 level. How many different wavelengths of light can be emitted as this excited atom loses energy?
Only certain transitions are allowed from one energy level to another. In one-electron species, the change in ℓ for an allowed transition is ±1. For example, a 3p electron can move to a 2s orbital but not to a 2p. Thus, in the UV series, where  nfinal = 1, allowed transitions can start in a  p orbital (ℓ = 1) of n = 2 or higher, not in an  s (ℓ = 0) or  d (ℓ = 2) orbital of  n = 2 or higher. From what orbital do each of the allowed transitions start for the first four emission lines in the visible series (nfinal = 2)?
Assume that a hydrogen atom’s electron has been excited to the n = 6 level. How many different wavelengths of light can be emitted as this excited atom loses energy?
You may want to reference (Pages 219 - 224) Section 6.3 while completing this problem.A certain quantum-mechanical system has the energy levels shown in the accompanying diagram. The energy levels are indexed by a single quantum number n that is an integer.Based on the drawing, put the following in order of increasing wavelength of the light absorbed during the transition.(i) n = 1 to n = 2(ii) n = 2 to n = 3(iii) n = 2 to n = 4(iv) n = 1 to n = 3
The hydrogen atom can absorb light of wavelength 1094 nm.Determine the initial value of n associated with this absorption.        
The hydrogen atom can absorb light of wavelength 1094 nm.Determine the final value of n associated with this absorption.
You may want to reference (Pages 219 - 224) Section 6.3 while completing this problem.Consider a transition in which the hydrogen atom is excited from n = 1 to n = ∞. What will occur if light with a shorter wavelength than that required is used to excite the hydrogen atom?
A Bohr-model representation of the H atom is shown below with several electron transitions depicted by arrows:Rank the absorptions in terms of increasing wavelength of light absorbed.
The spectra of hydrogen and of calcium are shown in the following figure. What causes the lines in these spectra? Why are the colors of the lines different? Suggest a reason for the observation that the spectrum of calcium is more complicated than the spectrum of hydrogen.
Determine whether each of the following transitions in the hydrogen atom corresponds to absorption or emission of energy.a. n = 3 → n = 1b. n = 2 → n = 4c. n = 4 → n = 3
Classify each of the following statements as either true or false:(a) A hydrogen atom in the n = 3 state can emit light at only two specific wavelengths(b) A hydrogen atom in the n = 2 state is at a lower energy than one in the n = 1 state(c) The energy of an emitted photon equals the energy difference of the two states involved in the emission
Consider a transition of the electron in the hydrogen atom from n = 4 to n = 9.Will the light be absorbed or emitted?
You may want to reference (Pages 219 - 224) Section 6.3 while completing this problem.Consider a transition in which the hydrogen atom is excited from n = 1 to n = ∞. What is the end result of this transition?
You may want to reference (Pages 219 - 224) Section 6.3 while completing this problem.Consider a transition in which the hydrogen atom is excited from n = 1 to n = ∞. How are the results of Parts B and C related to the plot shown below?
Arrange the following H atom electron transitions in order of  increasing frequency of the photon absorbed or emitted:(a) n = 2 to n = 4               (b) n = 2 to n = 1(c) n = 2 to n = 5               (d) n = 4 to n = 3
Arrange the following H atom electron transitions in order of  decreasing wavelength of the photon absorbed or emitted:(a) n = 2 to n = ∞               (b) n = 4 to n = 20(c) n = 3 to n = 10               (d) n = 2 to n = 1
A Bohr-model representation of the H atom is shown below with several electron transitions depicted by arrows:Which transitions are absorptions and which are emissions?
The flame tests for sodium and potassium are based on the emissions at 589 nm and 404 nm, respectively. When both elements are present, the Na+ emission is so strong that the K + emission can be seen only by looking through a cobalt-glass filter. What does the cobalt-glass filter do?
An electron in the n=7 level of the hydrogen atom relaxes to a lower energy level, emitting light of 2166 nm. What is the value of n for the level to which the electron relaxed?
The energies, E, for the first few states of an unknown element are shown here in arbitrary units.
For this question consider the figure that shows an energy level diagram for a certain atom (not hydrogen). Several transitions are shown and are labeled by letters. Note: The diagram is not drawn to scale. Which transition corresponds to the emission of a 177 nm photon? Which transition corresponds to the absorption of a 124 nm photon?
Does the hydrogen atom "expand" or "contract" when an electron is excited from the n = 1 state to the n = 4 state?
Certain elements emit light of a specific wavelength when they are burned. Historically, chemists used such emission wavelengths to determine whether specific elements were present in a sample. Some characteristic wavelengths for some of the elements areAg328.1 nmFe372.0 nmAu267.6 nmK404.7 nmBa455.4 nmMg285.2 nmCa422.7 nmNa589.6 nmCu324.8 nmNi341.5 nmWhich element emits photons of highest energy?
Which of the following electron transitions requires the smallest energy to be absorbed by the hydrogen atom?A. from n = 1 to n = 2B. from n = 2 to n = 4C. from n = 2 to n = 6D. from n = 3 to n = 6E. from n = 4 to n = 6
Which transition between energy levels in a hydrogen atom corresponds to the shortest wavelength of light?1. 5 → 62. 2 → 53. 2 → 34. 3 → 55. 3 → 46. 2 → 4 
Which of the following transitions represent  absorption of a photon with the  highest frequency? n = 3 to n = 1n = 2 to n = 4n = 1 to n = 2n = 6 to n = 3n = 1 to n = 3 
Is energy emitted or absorbed when the following electronic transitions occur in hydrogen?from an orbit of radius 2.12 Å to one of radius 8.46 Å,
Suppose you have two unlabeled flasks, and each flask contains one of these two compounds:Can you differentiate the compounds using a UV spectrophotometer? Select the true statement.a. The λmax of the compound with 2 conjugated bonds appears at a longer wavelength than does the λmax of the compound with 3 conjugated bonds. b. The λmax of the compound with 3 conjugated bonds appears at a longer wavelength than does the λmax of the compound with 2 conjugated bonds.c. The two compounds cannot be differentiated by their λmax values.
According to the Bohr model for the hydrogen atom, which of the following transitions will emit light with the longest wavelength?a. from the n = 4 to n = 2 energy level.b. from the n = 4 to n = 3 energy level.c. from the n = 3 to n = 1 energy level.d. from the n = 6 to n = 2 energy level.e. from the n = 5 to n = 3 energy level.
For this question consider the figure that shows an energy level diagram for a certain atom (not hydrogen). Several transitions are shown and are labeled by letters. Note: The diagram is not drawn to scale. Which transition corresponds to the emission of the photon with the longest wavelength? Which transition corresponds to the emission of the photon with the shortest wavelength?
Which electronic transition in the hydrogen atom results in the emission of light of the shortest wavelength?A. n = 4 to n = 3B. n = 1 to n = 2C. n = 1 to n = 6D. n = 3 to n = 1E. n = 2 to n = 1
Which energy gap in the Bohr Model would be associated with the longest wavelength?(A) from n = 2 to n = 1(B) from n = 6 to n = 5(C) from n= 10 to n = 9(D) from n = 11 to n = 10(E) They have the same wavelength
Consider the following portion of the energy-level diagram for hydrogen:n = 4   –0.1361 × 10 –18  Jn = 3   –0.2420 × 10 –18  Jn = 2   –0.5445 × 10 –18  Jn = 1   –2.178 × 10 –18  JFor which of the following transitions does the light emitted have the longest wavelength?A. n = 4 to n = 1B. n = 4 to n = 2C. n = 4 to n = 3D. n = 3 to n = 2E. n = 2 to n = 1
Which of the following transitions represents the emission of a photon with the largest energy?A) n = 1 to n = 4B) n = 2 to n = 5C) n = 3 to n = 1D) n = 6 to n = 3E) n = 2 to n = 1
Which electron transition produces light of the highest frequency in the hydrogen atom?a. 2p → 1sb. 4p → 1sc. 3p → 1sd. 5p → 1s
Which of the following transitions (of the electron in a hydrogen atom) result from the emission of a photon with the largest energy?A) n = 2 to n = 5B) n = 2 to n = 1C) n = 1 to n = 4D) n = 6 to n = 3E) n = 3 to n = 1
What is an emission spectrum?
The bright lines of an emission spectrum are the result of _____.a. electrons being ejected from atomsb. electrons losing energy as they spiral into the nucleus of an atomc. electrons transitioning from a lower energy level to a higher energy leveld. electrons transitioning from a higher energy level to a lower energy level
The Lyman series of emission lines of the hydrogen atom are those for which nf = 1.Calculate the wavelengths of the first three lines in the Lyman series-those for which ni =2, 3, and 4.
Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n = 7 to the level n = 2.
What are the wavelengths, in nanometers, of the bright lines of the hydrogen emission spectrum corresponding to the transition: n = 5 to n = 2?
Atomic emission spectra are due to electronsa. being removed from an atom.b. in an atom rising from one energy level to a higher one.c. in an atom dropping from one energy level to a lower one.d. being added to an atom. changing state from solid to liquid. 
What is the wavelength (in nm) of the least energetic spectral line in the visible series of the H atom?