Title III Technology Literacy Challenge Grant

Learning Unit Overview | Content Knowledge | Essential Questions | Connection To Standards | Initiating Activity | Learning Experiences |

Culminating Performance | Pre-Requisite Skills | Modifications | Schedule/Time Plan | Technology Use

LU Title: Light and Elements Author: Pat Snell

Grade Level:11th and 12th Notre Dame Jr. Sr. High School

Topic/Subject Area: Physics Address: Notre Dame Lane Utica, NY 13502

Email: physicspat@aol.com Phone:315-724-5118

OVERVIEW

CONTENT KNOWLEDGE

Declarative Procedural

The student will be able to define terms associated with the study of light and atoms

The student will be able to read and understand information gathered on scientists of historical importance

The student will know what a wave is and how it behaves

The student will be able to conduct an electronic search for information and present written and oral information

The student will know the relationship between waves and energy

The student will be able to write a complete laboratory report after performing an experiment

The student will know the characteristics of the electromagnetic spectrum and be able to identify its parts

The student will be able to create a spreadsheet and graph from data collected in experimentation

The student will be able to cite examples of the wave behavior of light

The student will be able to take notes from oral presentations, analyze them, and write a culminating essay

The student will know the relationship between wavelength and frequencyThe student will know how light is related to the elements

ESSENTIAL QUESTIONS

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1. What correlation is there between light and waves?

2. What is the connection between energy and waves?

3. What is the connection between elements and waves?

4. What contributions by scientists were important to our understanding of waves, light, and elements?

 

CONNECTIONS TO NYS LEARNING STANDARDSList Standard # and Key Idea #: Write out related Performance Indicator(s) or Benchmark(s)

MST Standard #1

Scientific Inquiry # 1

Formulate questions independently with the aid of references appropriate for guiding the search for explanations of everyday observations

Seek to clarify, to assess critically, and to reconcile with their own thinking the ideas presented by others, including peers, teachers, authors, and scientists

Scientific Inquiry # 2

Use conventional techniques and those of their own design to make further observations and refine their explanations, guided by a need for more information

Develop, present, and defend formal research proposals for testing their own explanations of common phenomena, including ways of obtaining needed observations and ways of conducting simple controlled experiments

Carry out their research proposals, recording observations and measurements (e.g., lab notes, audio tape, computer disk, video tape) to help assess the explanation

Scientific Inquiry # 3

Design charts, tables, graphs and other representations of observations in conventional and creative ways to help them address their research question or hypothesis.

Interpret the organized data to answer the research question or hypothesis and gain insight into the problem

Modify their personal understanding of phenomena based on evaluation of their hypothesis

MST Standard # 2

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Information Systems # 1

Use spreadsheets and data based software to collect, process, display, and analyze information. Students access needed information from electronic data bases and on-line telecommunication services

Systematically obtain accurate and relevant information pertaining to a particular topic from a range of sources, including local and national media, libraries, museums, governmental agencies, industries, and individuals

Collect data from probes to measure events and phenomena

Information Systems # 2

Identify advantages and limitations of data-handling programs and graphic programs

MST Standard # 3

Measurement #5

Estimate, make, and use measurements in real-world situations

Explore and produce graphic representations of data using calculators/computers

Patterns/Functions # 7

Develop an understanding of functions and functional relationships: that a change in one quantity (variable) results in change in another

MST Standard # 4

Physical Setting # 4

Describe the sources and identify the transformations of energy observed in everyday life

Observe and describe energy changes as related to chemical reactions

MST Standard # 5

Computer Technology # 3

Use a computer system to connect to and access needed information from various Internet sites

 ELA Standard # 1

ELA Standard # 2

INITIATING ACTIVITY

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1. Provide small groups of students with a length of rope. Have students produce waves by moving one end of the rope while the other is held still. Lead them to determine how to increase the frequency and how to increase the amplitude of the waves.

2. Give students a prism and a flashlight. Have the students pass the white light through the prism. Explain that as the light passes through the prism, the higher frequencies are bent more than the lower frequencies. Determine that they have seen the spectrum before in the form of a rainbow. Lead students through a discussion of frequencies and how they now know that white light has different frequencies. They should reach the conclusion that scientists can use this knowledge to develop new theories, products, and knowledge.

3. Information gathered from the above activities should be recorded in their notebooks and should include definitions to the following terms:

wavelength light

frequency electromagnetic spectrum

amplitude prism

  angstrom radial velocity

Doppler shift Radiation

LEARNING EXPERIENCESIn chronological order including acquisition experiences and extending/refining

experiences for all stated declarative and procedural knowledge.

1. Assign research project – Elements / Light Appendix # 1

2. Lecture with notes to present the basic ideas of light, waves, element spectra, and to review the idea that compounds are made up of elements. Present the idea that the elements in a compound can be determined by the spectra they produce.

3. Visit website:www.geo.mtu.edu/rs/back/spectrum

See Appendix # 5

4. Visit website: http://cse.ssl.berkeley.edu/light/light_tour,html

5. Measuring the Wavelengths of Light Waves Observing the Spectra of a Compound – Appendix # 3

6. Spectral Analysis of Stars.

7. Balmer Series of Hydrogen.

8. Photoelectric effect of metals.

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CULMINATING PERFORMANCE Include rubric(s)

After researching and hearing about the research of others, write an essay, of at least 3 paragraphs, that answers the following questions:

In your opinion, which of the scientists studied made the best contribution to our understanding of light and the elements? Why?

How does this apply to your daily life?

PRE-REQUISITE SKILLS

Prior to beginning the unit on elements / light, the students will have in place the following skills:

Word processing

Note taking

Graphing (including spreadsheet) using Excel

Independent reading for knowledge

 

MODIFICATIONS

 The teacher must present the unit by incorporating a variety of teaching styles in order to adapt to the various learning styles of the students. Arrangements should be made in advance with the school’s media center and computer lab in order to coordinate necessary research. Resource teachers should be informed in advance in order to make sure that modifications are in place and I.E.P. guidelines are followed throughout the unit.

 UNIT SCHEDULE/TIME PLAN

Total time : 3 weeks.

Written projects require 2 weeks.

Presentations require approximately 3 class periods.

Laboratory experiences require approximately 6 class periods including write ups.

Lecture: 1 to 1 ½ class periods

Website visits may be done during study halls or at home.

Essay preparation and writing may use a combination of class time and home time.

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TECHNOLOGY USE

Excel spreadsheet and graph

Electronic research

Websites:

- www.psrc-online.org/classrooms/papers/taylor.html

- www.psrc-online.org/problem/~cfprobwk9.html

- http://cse.berkeley/edu.light/light_tour.html

- http://www.geo.mtu.edu/rs/back/spectrum/

CD-Rom Multimedia Physics. Pro one Software; Las Cruces, NM

Eyewitness Encyclopedia of Science; Dorling Kindersley Multimedia; New York

APPENDIX # 1 Elements / Light

Project for Physics

Purpose: To research a scientist and determine his/her contribution to our knowledge of atoms and light. The student should be able to present his information to the class orally and visually, as well as in written form.

Topics: Choose one of the following scientists. Using electronic as well as paper research, determine the following:

1. date of birth and death, education, facts about his/her life

2. contributions to our knowledge of atoms and light

3. How did these contributions affect your study of physics and your daily life?

4. Integrate the setting of the person and his/her research

5. Determine the historical time period in which the scientist worked. Relate the work done to world events.

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The student must prepare a written report and present an oral report to the class. Visual aids must be included as well as references. Grading will be based on the rubric presented below.

Dates: The student will have 2 weeks to complete his research and write his paper. Oral presentations will begin on the date the written reports are due and continue until finished.

List of Scientists for Oral Reports:

Anderson Angstrom Becquerel

Bohr Compton Dalton

De Broglie Doppler Einstein

Fraunhoef Franklin Grimaldi

Heisenberg Hertzsprung Huygens

Hertz Mayer, Marie Maxwell

Michelson Millikan Newton

Pauli Planck Roemer

Rutherford Thompson Young

Snell

Essay Rubric for Oral Report:

1. Historical facts and education 1 2 3 4 5

2. Contribution 1 2 3 4 5

3. Effects on Physics 1 2 3 4 5

4. Effects on your daily life 1 2 3 4 5

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APPENDIX # 2Objectives of the Labs –

1. Use conventional techniques to further observations.

2. Develop research proposals for testing their own explanations.

3. Carry out research proposals record observations to assess the explanation.

4. Design charts and graphs of observations to help support their hypothesis.

5. Interpret data to answer their hypothesis.

6. Modify their personal understanding of phenomena based on their evaluation of the hypothesis.

7. Use a spreadsheet and data based software (excel) to collect, process, display and analyze information.

Laboratory Investigation #1 – The Spectra of Elements Combined

Purpose: To show that when to elements combine in covalent bonding, their spectral lines are identifiable in the spectra of the resulting compound.

Materials: gas tubes of the elements oxygen and hydrogen and the compound water, a power unit for each tube.

Procedure:

1. Observe and record the bright lines as to color and position for the elements hydrogen and oxygen.

2. Compare your observations to standard plates of the hydrogen and oxygen spectra.

3. Observe and record the spectra of water as to color and position of the bright lines.

Conclusion:

How did the spectra of the elements compare to the spectra of the compound water? How did the spectra of the compound compare to the ionic compound spectra you observed in the flame test? Describe the differences and similarities. How can this be applied to other situations? How do these results compare to a mass spectrograph?

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Laboratory Investigation #2- Balmer Series of Hydrogen

1. Observe and record the colors of the bright line spectrum of hydrogen

2. Observe and record the colors of the bright line spectrum of helium

3. Determine the wavelength of light for n = 2 to n = 1. Use the formula: = hC___ E2 – E1 Show all work.

a. Is the wavelength visible?

b. If so, in what range?

c. What two formulas were used to derive?

4. What wavelength is emitted in hydrogen when the transition is n = 6 to n = 2?

Use: 1 = R 1 - 1 R = Rydberg constant n2f n2I 1.097 X 107 m-1

5. Use the formula above to determine the transition for the other 4 colors.

Use the Bohr model to determine the ionization energy of He+

(use E1 = Z2 = 22 = 4 times E, for H)

(Use = c = hc) What is the minimum for the photon? _n_f = l

6. Explain why the spectrum of helium is so different from hydrogen.

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Laboratory Investigation #3 – Measuring the Wavelengths of Light Waves

Apparatus

Diffraction Grating Support for the Grating Two Meter Sticks

Power Unit Neon or Other Discharge Tube

While doing this investigation you will: Observe the interference pattern of diffracted light Use this to measure some typical wavelengths of light. Determine the energy content of each color.

When light is shone upon a diffraction grating, it is diffracted by the slits in the grating. An interference pattern results. While looking through the grating, you will be able to see the spectrum of the source to the right and left of the position of the source. The spectrum will consist of several lines of different colored light.

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= tangent

L

= Distance from central Maxima.

L = Distance to Source.

By measuring and L and calculating the tangent of , you can look up the sine of . In the small triangle db.

= sin

d

and so,

= d sin You will use this equation to find the wavelengths of the light emitted by your source.

Procedure

1. Be sure that your light source is vertical and fastened against the 50cm mark on the meter stick. The distance along the meter stick from the grating to the source is L. Set L at some even value such as 60cm or 80cm.

2. To measure have your lab partner move a ruler along the outer edge of the meter stick until it is exactly in back of a line you observe while looking through the grating. Measure as the distance between the 50cm mark and the position of the line. Record this value in the Table.

3. In the equation = d sin , d is the distance between two lines in the grating. Your teacher will either give you the value of d or tell you the number of lines per centimeter in the grating. Given the number of lines per centimeter (N), d will equal - 1cm

N 4. Use your value of d to complete the last column of the Table for each observed line.

Data and Observations

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Color of Line

Distance from source to first order lines ()

(cm)

Distance from source to

grating (L) (cm)

Tan L

Angle (*)

Sin Wavelength, = d sin

(cm)

Interpretations:

Compare the wavelength of the light, its frequency and energy.

Laboratory Investigation #4: Spectral Analysis of Stars

Objective: To observe spectrograms of light sources produced by several different gases. Properties of stars will be determined by analyzing their absorption line spectra.

Procedure:

1. Observe the spectra from the gas tubes sources supplied by your instructor. Draw the spectrogram using colored pencils of each gas. Label each spectrogram.

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2. Referring to the top of diagram #1 and a chart of the electromagnetic spectra label the red and blue ends of the angstrom wavelength line.

3. Referring to diagram #1, which shows laboratory spectrum hydrogen Balmer absorption lines measure the wavelength of each absorption line. Record your observations in report sheet #1.

4. Measure the wavelength of the hydrogen line in star A. Determine the difference in angstroms between the stars hydrogen Balmer line and the line produced in the laboratory. Record under wavelength difference in report sheet #2.

5. Determine the shift in the hydrogen Balmer line of star A. Record whether the shift is toward the red or the blue line of the spectra. Record this under shift direction on the report sheet.

6. Using the equation below, calculate the radial velocity of star A. Label and record your answer and show all work.

V= x C

7. Repeat procedures 3-6 for star B. Record your data.

8. Use diagram #2 which shows the absorption lines of selected elements to determine the composition of the sample star spectra shown below diagram #2. Record your answers on report sheet #4.

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Report Sheet #1Hydrogen Spectrum Wavelengths

Absorption Line

ALPHA ()

BETA ()

GAMMA ()

DELTA ()

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Report Sheet #2

Comparing Two Stars

Star A Star B

Hydrogen Line Hydrogen Line

Wavelength Difference Wavelength Difference

Shift Direction Shift Direction

Radial Velocity Radial Velocity

Calculations: Calculations:

Report Sheet #3

Elements of Star Spectrum

Element Symbol

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Conclusive Paragraph:

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Appendix #3

Photoemissive Metals

Graph the following:

Silver PlatinumFrequency(X 1015 Hz)

Kinetic energy(e) Convert to Joules

Frequency(X 1015 Hz)

Kinetic energy(e) Convert to Joules

1.5 1.5 1.5 0.6

2.0 3.6 2.0 2.5

3.0 7.5 3.0 6.9

4.0 12.0 4.0 10.9

5.0 15.9 5.0 15.0

1. The slope of the silver line is____________________________.

Show work:

2. The slope of the platinum line is_________________________.

Show work:

3. The threshold frequency of silver is_______________________.

4. The work function of silver is____________________________.

5. The work function of platinum is_________________________.

6. (Kemax = hf – wo) a photon with an hf of 2 e will release photoelectrons of __________________________ from silver.

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7. The same photon will release photoelectrons of __________________________from platinum.

Conclusion:In a well-constructed paragraph, compare the slopes of the two metals, threshold frequency, work function, and maximum kinetic energy (Kemax). Include similarities, differences and applications.

Line graphing Rubric:

1. Title/Number 1 point

2. Purpose 1 Point

3. Background 3 points

4. Hypothesis 2 points

5. Data (Spreadsheet) 2 points

6. Graph 1 point

7. Conclusion (reference graph and hypothesis) 5 points

8. Future questions- applications 5 points

Final Essay

Explain what you have learned about light and elements. How does what you have learned apply to your daily life (reference three examples).

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