Honors Page 1 of 41 Name:

Class:

Honors Chemistry

1: Up and Atom Topics/ Daily Outline:

Day A B Content: TEXT CW #: HW #:

1 9/16 9/17 Evidence for the big bang -- 1, 2, 3 -- 2 9/18 9/19 Waves 5.3 4, 5 --

3 9/20 9/23 Atomic emission spectra 5.3 6, 7 1

4 9/24 9/25 Flame Test Lab, Quiz 5.3 -- -- 5 9/26 9/27 Element creation, Atomic structure 25.3, 4.3 8, 9, 10 --

6 10/1 10/2 Atomic structure, Isotopes 4.3 11 2

7 10/3 10/4 Spectroscopy Lab/ Flex Day -- 12 3 8 10/7 10/8 Review -- -- --

9 10/10 10/11 Unit Test -- -- --

Homework:

1. HW 1: Review for Quiz 2. HW 2: Isotopes Practice 3. HW 3: Review for Unit Test

Important Due Dates:

• SciResearch: 3 Select a Topic of Research, 9/18 (A Day) and 9/19 (B Day)

• Index Card Assessment, 9/20 (A Day) and 9/23 (B Day)

• SciResearch: 4 Conduct a Literature Review, 10/1 (A Day) and 10/2 (B Day)

• Flame Test Lab Report, 10/3 (A Day) and 10/4 (B Day)

• SciResearch: 5 Develop the Question or Problem, 10/10 (A Day) and 10/11 (B Day)

• Who Tagged the Lab Bench Conclusion, 10/17 (A Day) and 10/18 (B Day)

For tutorials and additional resources:

www.leffellabs.com

If you are absent, use this sheet to determine what you missed and collect the appropriate materials from your teacher. Get help from a friend, the link above, or the instructor.

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CW 1: The Beginning of Everything

Link: http://www.youtube.com/watch?v=wNDGgL73ihY

1. What evidence helped change scientist’s minds that the universe was infinite and ageless?

2. If the big bang wasn’t an explosion, what was it?

3. During the quark era, what was the relationship between energy and matter? Why?

4. What happened to the particles as the universe cooled during the nucleosynthesis era?

5. How were the first stars formed?

6. How does the universe “experience itself?”

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CW 2: Just a Theory

The word theory, unfortunately, is misused in everyday language. Link: http://www.youtube.com/watch?v=gklQ3GbmufI

1. What are the four requirements of a scientific theory?

2. Why is the phrase “evolution is just a theory” incorrect?

3. Can a scientific theory be changed?

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CW 3: Evidence of the Big Bang

Doppler Shift Interactive Link: http://goo.gl/2jMeFL

1. Click on the “Introduction” tab. a. How are the light from a star and the sound from an ambulance similar?

b. What can we learn by carefully measuring the frequency of light emitted by stars?

2. Click on the “How To” tab. a. What do the green circles represent? The yellow circles?

b. What is the frequency of a wave?

c. What is the wavelength of a wave?

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3. Click on the “Interactive” tab. a. The green light on the spaceship represents a sensor that can detect light from

the nearby star. b. Sketch an example of a wave with a long wavelength.

c. Sketch an example of a wave with short wavelength.

d. Which one would have a higher frequency? Why?

4. Click on the “Source Approaches” button. a. What happens to the wavelength of the light as the star approaches the sensor?

b. What happens to the wavelength of the light as the star moves away from the sensor?

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Edwin Hubble is credited with discovering that the universe is expanding. He accomplished this by comparing the spectral lines emitted by elements for far away stars. Each element has its own distinct set of spectral lines, like a fingerprint.

5. Based on the pattern of spectral lines from the distant star, what element is shown?

6. How does this compare to the spectral lines for that element on Earth?

7. How does this relate to red shift and the Big Bang?

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Picture of the Big Bang

Video link: http://www.youtube.com/watch?v=_mZQ-5-KYHw

8. What is the cosmic background radiation? How can we detect it?

9. During the “red hot cosmic soup” phase of the universe, how did light behave?

10. As temperatures cooled to just below the temperature of the sun, what happened to electrons and protons? What did they form?

11. How did this change the way light moved through the universe?

12. When this light reaches Earth, what happens to its color?

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13. What is the temperature of empty space?

14. What caused small variations in the cosmic background radiation?

15. Why did these variations get larger?

Journal Write 1 The following are major lines of evidence to support the Big Bang theory.

• As light travels from distant stars, the stretching of space time causes this light to shift towards more red wavelengths.

• The cosmic background radiation is distributed relatively uniformly across the universe, with small variations due differences in mass.

How do each of the parts in this assignment address these lines of evidence? Explain.

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CW 4: Waves

Properties of Waves Electromagnetic waves carry vibrations in electrical and magnetic fields. The entire wave can be thought of as extending infinitely in both directions. The wavelength (λ) is the distance between two consecutive peaks (or troughs) in the wave. The frequency (f) of a wave is defined as the number of wavelengths per second which travel past a given point.

Figure 1

Figure 2

1. On each figure above, draw a line connecting two points whose separation is equal to

the wavelength. If there is more than one way to do this, draw a second line.

2. If both waves are travelling at the same speed, which one has a greater frequency?

3. For a wave traveling at a given velocity (v), how does the frequency depend on the wavelength, if at all?

Wavelength (nm) Frequency (1/s or s-1) Energy (J) 333.1 9.00x1014 5.963x10-19

499.7 6.00x1014 3.976x10-19 999.3 3.00x1014 1.988x10-19

Table 1

4. Based on the information in Table 1, a. As the frequency of a wave increases, the energy _______________________.

This relationship is proportional / inversely proportional (circle one). b. As the wavelength of a wave increases, the energy _______________________.

This relationship is proportional / inversely proportional (circle one).

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The Electromagnetic Spectrum

The electromagnetic spectrum covers a range of wavelengths and energies. Light used to "see" an object must have a wavelength about the same size as or smaller than the object – for example, a light microscope is used to view cells.

5. What kind of electromagnetic radiation has the shortest wavelength? The longest?

6. What kind of electromagnetic radiation could be used to "see" molecules? A cold virus?

7. A certain photon of electromagnetic radiation has a wavelength of 100 nm. In what region of the electromagnetic spectrum should this photon be classified?

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Visible Light Spectrum

8. Why are the color labels plural (i.e., “Reds” rather than “Red”)?

9. What is the speed of light? Does it change for different colors?

10. Which color corresponds to the longest wavelengths? The shortest wavelengths?

11. Which is the more energetic, a red photon or a blue photon? Explain.

12. Write a sentence that describes the relationship between wavelength and energy of light.

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The Wave Equation

Waves are described by their velocity (v), frequency (f), and wavelength (λ). In a vacuum (empty space) all electromagnetic waves travel at approximately 3.0x108 m/s (the speed of light, c), the fastest speed possible. The frequency of a wave is represented by hertz, which

has unit of 1

𝑠 or s-1. Wavelength is measured in meters. For visible light, nanometers are

typically used. 𝑣 = 𝑓𝜆 𝑣 = 𝑠𝑝𝑒𝑒𝑑 𝑜𝑓 𝑙𝑖𝑔ℎ𝑡 (𝑐) = 3.0 × 108 𝑚/𝑠

Light can be thought of as electromagnetic radiation having a particular wavelength and frequency. Electromagnetic radiation can be viewed as a stream of particles known as photons, each of which has a specific amount of energy associated with it.

𝐸𝑝ℎ𝑜𝑡𝑜𝑛 = ℎ𝑓 ℎ = 6.626 × 10−34 𝐽 ∙ 𝑠

13. Define each of the following terms. Variable Name Units

v

f

λ

Constant Name Value

c Speed of light

ℎ Plank’s constant

14. What is the frequency of green light, which has a wavelength of 490 nm?

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15. Which is the more energetic, a red photon (λ ~ 700 nm) or a blue photon (λ ~ 400 nm)? Calculate both energies.

16. A photon has a frequency of 1.50x1014 s–1. What is its wavelength in nm, and what region of the electromagnetic spectrum would it be found in?

17. A photon has a wavelength of 1.00x10–9 m. What is the energy and frequency of this photon?

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CW 5: Spectroscopy of the Stars

Video link: http://www.youtube.com/watch?v=n_KyYFYNvpI

1. What happens when you heat up or burn a chemical element? 2. What does the spectrum of light from our sun look like? What is unusual? 3. What is the relationship between the absorption lines on spectrum and the light

emitted by our sun?

4. How can we determine which elements are being burned by a star?

5. What is the same, wherever we look across space?

Journal Write 2 From observing the light of many galaxies, scientists have found that the ratio of elements throughout our observable universe is constant. This means that the chemical elements in the cosmos are very well mixed. How does this support the Big Bang theory? Explain.

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CW 6: Atomic Emission Spectra

Navigate to unit 1 on www.leffellabs.com. Download the “1 Atomic Emission Spectra” file. View the PowerPoint as a slide show, answering the questions as you progress.

1. What is electromagnetic radiation?

2. How does a spectrum form?

3. Why is the spectrum formed by a helium lamp different than the spectrum formed by a white light bulb?

4. Can you identify the element(s) present in the unknown? Justify your answer and explain how you came to it.

5. Why did Bohr choose to study hydrogen?

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6. What happens to the distance between energy levels as they increase?

7. Draw and label the Bohr model of the atom. Summarize the basics.

8. Explain how the picture relates to atoms and the Bohr model.

9. Compare the ground state and the excited state.

10. Explain how electrons move between energy levels.

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11. Only certain frequencies of light are visible to the human eye. List all the visible energy transitions found in hydrogen and the color of light they give off.

12. Compare the energy transitions in the ultraviolet and infrared frequencies. Then circle the correct words in the sentence below.

The energy given off during an infrared transition is too (small/large) to be seen by the human eye, whereas the energy given off during an ultraviolet transition is too (small/large) to be seen by the human eye.

13. Use the emission spectrum to explain why the color given off by copper is blue green.

14. What is a flame test? Explain.

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CW 7: Flame Test Lab

Video Link: http://www.youtube.com/watch?v=65aWaDGNfVE

• Watch the video. • In your groups, write the purpose, procedure (step by step, numbered; spare no

details!), and materials needed for the lab. • NOTE: We will not do it exactly like in the video. Observe the materials we will use and

adjust your procedure accordingly.

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1: Up and Atom Flame Test Lab Report Your final lab report should be typed. The following sections should be completed, in order, as they appear below. COVER SHEET: A cover sheet with nothing else but:

• Title of the lab: A short, descriptive, title that tells the reader what the lab is about.

• Your name

• Your partners’ first and last names

• Due date of the lab report

• Class period PURPOSE: What are we trying to determine/ do in this experiment? PROCEDURE: A paraphrased procedure for setting up the experiment and collecting data over the course of the experiment. Underline any materials you will need once you have written the procedure. This should be a paragraph explaining what you did, especially any changes to the original written procedure. DATA: Organize ALL data into a neat data table. This means you will need in depth observations. Things to observe:

• Color of each of the flames (knowns and unkn

• owns)

• Color of each of the solutions (knowns and unknowns)

• Anything unusual, hard to see, unclear, etc. CONCLUSION: Answer the following questions using complete sentences. You will be graded on the quality, completeness, correctness, and style of your writing.

1. Use the Bohr model of the atom to explain how electrons move between energy levels and emit light. What supplied the energy for the electrons to move between energy levels in this experiment?

2. In this lab, you observed that each metal ion produced a different color flame. Explain why each flame was a unique color. In your answer, include

a. discussion of the electromagnetic spectrum b. the relationship between wavelength, energy, and color c. an application of this phenomena (search online, cite source)

3. Does the flame test provide a good method for identifying unknown elements? Explain and justify your answer.

4. Correctly identify the two unknown samples and explain how you identified them.

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Grading Rubric Cover Page

• Title of the lab

• Your name

• Your partners’ names

• Due date of the lab report

• Class period

/2.5

Purpose

• Clear statement about what we set out to do with this lab

/2.5

Procedure

• Repeatable, clear

• Paragraph form

• Materials are underlined in procedure

• Complete, no steps skipped or assumed

/5

Data

• Table is neat, organized, readable, complete

• Reflects student understanding of lab concepts and practices

• Quality/ completeness of observations

/10

Conclusion

• Question 1: 5 points

• Question 2: 10 points

• Question 3: 5 points

• Question 4: 5 points

/25

Mechanics

• Academic, 3rd person, passive voice writing style

• Cite any sources using a major style (APA, MLA, etc.)

• Correct format

/5

TOTAL:

/50

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CW 8: Star Death and the Creation of Elements

Video Link: http://www.youtube.com/watch?v=DEw6X2BhIy8

1. What is the relationship between outward pressure, the energy released in a core of a star, and the force of gravity?

2. What occurs during “stage 1” of the fusion process?

3. What needs to happen before “stage 2” can start?

4. What two things happen during helium fusion?

5. Why will our sun die after it runs out of helium?

6. Why are more massive stars required to make elements heavier than oxygen?

7. What happens when the core of the star has been converted into iron?

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CW 9: Fission vs. Fusion

Video Link: http://www.youtube.com/watch?v=FU6y1XIADdg

1. What is meant by nuclear stability?

2. What is binding energy?

3. Oxygen-16 is made of 8 protons and 8 neutrons. Complete the following:

moxygen-16 nucleus: ________________ 8 mproton + 8 mneutron: ___________

4. Where did the missing mass go?

5. How much energy would be released for a mole (16 grams) of oxygen?

6. How much coal would you need to burn to release this same amount?

7. What is a fission reaction?

8. What is a fusion reaction?

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9. How do nuclear power plants use the energy released during fission?

10. What is a chain reaction?

11. How are chain reactions controlled, preventing melt downs?

12. What temperatures are required to fuse nuclei? Why?

13. What advantages does fusion have over fission, in terms of usable energy from power plants?

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CW 10: Atomic Structure

Isotope Notation

𝐶6

12 𝐶613 𝐶6

14 Carbon-12 Carbon-13 Carbon-14

Protons: _____ Neutrons: _____

Protons: _____ Neutrons: _____

Protons: _____ Neutrons: _____

1. Based on the pictures above, complete the table below.

Particle Charge Location

Proton

Neutron

Electron

2. Look at the notation: 𝐶6

12 . a. The bottom number is called the atomic number. What does this number

represent? What is the atomic number always equal to?

b. The top number is the mass number. How do you get this number?

3. What is always the same for an atom of carbon – the mass number or the atomic number?

4. What can vary for an atom of carbon – the mass number or the atomic number?

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Ions: Charged Particles

In a neutral (uncharged) atom, the number of protons is equal to the number of electrons. Ions are charged particles that are formed when an atom gains or loses electrons.

• When an atom loses electrons, its charge becomes positive (a cation).

• When an atom gains electrons, its charge becomes negative (an anion).

5. Look at the carbon atoms on the previous page. All of the atoms are neutral, or unchanged. Using the number of protons and electrons, explain how we know that these atoms are neutral.

6. An atom has 11 protons and 10 electrons. What is the identity of the atom and what is its charge?

When an atom has a charge, the charge is written as a superscript number after the element symbol. If the atom is neutral, there will be no number. The mass number and atomic number may or may not be included, depending on what information is needed.

𝑁𝑎+11123 𝑁𝑎+1 𝑁𝑎11

23 𝑁𝑎

7. Complete the table below.

# of Protons # of Electrons Were electron gained or lost? Cation, Anion, Neutral?

O

Cl-1

Cu+2

Cu+3

S-2

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8. Using the information provided and the table of elements, complete the table below.

Element Symbol

Atomic Number

# of Protons

# of Neutrons

# of Electrons

Mass Number

Net Charge

Cation, Anion, or Neutral

𝐶612 6 6 6

20 24 20 44

17 17 18 17

1 1 0 0

17 17 37

8 8 8 16 0

20 18 40

6 6 6 13

17 18 35 -1

6 10 12

8 16 -2

22 22 24 21

1 1 1

22 26 19 48

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CW 11: What are Isotopes?

• Go to http://phet.colorado.edu/en/simulation/isotopes-and-atomic-mass. Click on the picture.

• Press the green plus symbols next to “Symbol” and “Abundance in Nature”.

• Change the scale to read Atomic Mass (amu).

1. Look at the isotopes on the scale. This is hydrogen-1. Hydrogen-2 and hydrogen-3 can be made by dragging and adding neutrons. For each isotope of hydrogen, complete the table below.

Isotope # of

Protons (red)

# of Neutrons

(gray)

Atomic Number

Mass Number

Symbol Mass (amu) Abundance

Hydrogen - 1

Hydrogen - 2

Hydrogen - 3

2. Each type of hydrogen above is called an isotope. What is the same for isotopes? What

is different? Write a definition for “isotope”.

3. Which isotope of hydrogen is most abundant in nature?

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Weighted Average of Isotopes

• Choose the “Mixtures” from the bottom of the screen.

• Press the green plus symbols next to “Percent Composition” and “Average Atomic Mass”. This may already be done for you. If so, it will appear as a red minus symbol.

• Check to make sure your screen is toggled to “My Mix” by clicking the correct button.

4. Select Si from the table of elements. Look at the three containers of isotopes. What are the isotopes of Si?

5. Find Si on the table of elements. What is the name of Si?

6. Use the key on the table of elements to find the atomic mass of Si. What is the atomic

mass of Si?

7. Add one of each isotope of Si to the black box.

8. What happens to the average atomic mass if more silicon-30 is added to the mix?

9. What happens to the average atomic mass if more silicon-28 is added to the mix?

10. Using at least one of each isotope, try to make the average atomic mass match the value you found on the table of elements (question 6). YOU WILL NOT HAVE 33.33% FOR ANY OF THE ISOTOPES!!!

11. Toggle the screen to “Nature’s Mix”. Compare the percentages of each isotope.

Isotope My Mix Nature’s Mix

Silicon-28

Silicon-29

Silicon-30

12. Give evidence to support or dispute: “In nature, the chance of finding each isotope of an

element is equal.”

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Weighted Average Calculations

13. Magnesium has three isotopes. Find the average atomic mass of magnesium if:

• Isotope A has an abundance of 78.99%, with a mass of 23.9850419 amu,

• Isotope B has an abundance of 10.00%, with a mass of 24.9858370 amu,

• Isotope C has an abundance of 11.01%, with a mass of 25.9825930 amu.

Isotope % Abundance Decimal Atomic Mass of Isotope

Weighted Mass

SUM:

14. The element copper has naturally occurring isotopes. Copper-63 has a relative

abundance of 69.2% and a mass of 62.93 amu. Copper-65 has a relative abundance of 30.8% and a mass of 64.93 amu. Calculate the average atomic mass of copper. (Hint: Set up like the table above!)

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15. Calculate the average atomic mass of bromine. One isotope of bromine has an atomic mass of 78.92 amu and a relative abundance of 50.69%. The other major isotope of bromine has an atomic mass of 80.92 amu and a relative abundance of 49.31%. (Hint: Set up like the table above!)

16. There are two naturally occurring isotopes of gallium: Gallium-69 with a mass of 68.93 amu and Gallium-71 with a mass of 70.92 amu. Without doing any calculations, look at the periodic table and determine which isotope of gallium has the higher natural abundance. Explain your answer.

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CW 12: Who Tagged the Lab Bench?

Objective At the end of class, the teacher noticed fresh tagging on one of the lab benches. There were two students sitting at the bench, each writing with a different marker. The teacher confiscated the pens from the students. Your job is to determine which marker (and which student) wrote on the lab bench.

Background

Pen ink is a solution, with several dye molecules as the solute, and petrochemicals as the solvent. Although many inks appear to be the same color of blue, this color was achieved by blending a specific mixture of dye molecules. Each ink formulation is specific for the manufacturer. Forensic scientists can study the chemical makeup of pen ink to determine what type of pen a sample came from.

1. What is a solution?

2. What are the components of a solution? Ink can be used on many different surfaces, so it is important to consider what type of surface the ink will be used on as well as how permanent the ink should be. For example, children’s markers are often washable; meaning that they can be easily washed away with water. However; an artist might not want their precious work to wash away. Dye molecules can be polar or non-polar in nature, depending on what purpose the ink will be used for.

3. What type of solvent do you predict is used in children’s washable markers? Justify your answer with evidence.

4. What type of solvent do you predict is used in a Sharpie marker? Justify your answer with evidence.

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To examine the specific dye molecules found in each marker, we will use spectroscopy. Spectroscopy involves exposing a liquid sample to light. The light with either transmit through (go straight through) the sample or it will be absorbed by the molecules in the sample. The spectrometer then records how much light was absorbed and at each wavelength, generating a graph of absorption versus wavelength. This graph is called a spectrum and it is characteristic for each atom or molecule, like a fingerprint for the atom or molecule.

5. Is it possible that any of the above spectra are for the same molecule? Support your answer using evidence from the spectra.

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6. The following spectra were generated from the two samples shown below, both of which came from the same marker. Why does one sample absorb more light than the other at the given wavelength?

7. Based on your previous answer, revisit question 5. Should you change your answer? Why?

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Materials

• Solvent (1:1 isopropyl alcohol/ water)

• Laptop with Logger Pro

• 3 cuvettes (blank, marker A, marker B)

• Disposable pipet

• Spectrophotometer (SpectroVis)

• Paper towel

• Scissors

• Confiscated student markers

Procedure

1. Log on to the laptop. Open Logger Pro on the desktop and connect the SpectroVis.

2. Fill a cuvette to the line with the solvent. Place the cuvette into the SpectroVis according to the diagram.

3. On Logger Pro, select Experiment, select Calibrate, select Spectrometer 1. Allow the lamp to warm up, then select Finish Calibration, then click OK.

4. On a paper towel, use one marker to draw and color in a 2 cm by 2 cm box. Using the other marker, draw and color in a separate 2 cm by 2 cm box. Keep track of which sample is which.

5. Cut out each sample so that you have the colored box on the bottom and about 2 inches of blank paper towel on top, as shown in the diagram.

6. Roll one paper towel sample and place it into a cuvette. The side with the marker sample should be at the bottom of the cuvette. Use the dropper bottle to slowly add solvent to the cuvette. Keep track of which sample is which.

7. Wait 2 minutes. Some of the ink should travel into the solvent. Please note that your solution in the cuvette does not have to be very dark, but you should be able to see that it has ink in it.

8. When you are done, pull the paper towel out of the cuvette and dispose.

9. To take your first reading, place the first cuvette into the SpectroVis. Click on the green Collect button on the top, right hand corner. You should see a complete spectrum. When you are done, click on the red Stop button. At the left of the data table, if you double click the header, you can edit it to show the sample letter you ran.

10. Repeat step 9 for the other sample. Select “Store last run” when prompted. This allows you to have both spectra on the same graph. Make sure to go back and enter the sample letter.

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Data

Confiscated Student Markers Spectra

Tagging Marker Spectrum

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Analysis Questions

8. Compare your confiscated student marker spectra to another group. Record at least two similarities and two differences.

9. Repeatability is critical in science. Given that the results of this lab could get someone in trouble, how confident are you in the repeatability of your data?

Conclusion

Mr. Myers and the Student Resource Officer have been eagerly awaiting the results of your lab to know who to hold responsible for vandalism. Based on your work, you have two choices:

• If you are sure of the identity of the tagger, then write a referral to Mr. Myers identifying your claim of who tagged the desk. Cite evidence the lab and explain how the evidence supports your claim. Consequences for tagging can include being suspended from class, getting a ticket and a court date from the SRO, having to pay for damages, and/or being placed on probation.

o For this option, go to leffellabs.com, then go to the unit 1 page. Download the and complete the document titled “1 Who Tagged the Bench Referral”.

• If you are not sure of the identity of the tagger, then write an email to Mr. Myers explaining your findings. Cite evidence the lab and explain how the evidence supports your claim that the identity cannot be determined.

o For this option, go to leffellabs.com, then go to the unit 1 page. Download the and complete the document titled “1 Who Tagged the Bench Email”.

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Reference Materials