LESSON PLAN
Name: Maryann Sorey
Title of lesson: Electromagnetic Radiation but Mostly, Visible Light
Date of lesson: N/A
Length of lesson: (1) 50 Minute Lesson
Description of the class:
Name of course: AP Chemistry
Grade level: 12 th Grade
Honors or regular: AO
Source of the lesson :
The dark recesses of my mind.
TEKS addressed:
This lesson will in part satisfy the “Guide for Recommended Laboratory Programs” recommendations that students should have “Familiarity, involving more than a single day’s experience with general types of chemical laboratory work as… spectroscopy/calorimetry” ( page 39)
- Overview
Students will understand that a chromohore absorbs a particular wavelength and the color that we see is the reflected complementary color. This will give insight into the manner in which a colorimeter measures the absorption of light of a particular wavelength and will also familiarize them with the Spec 20.
II. Performance or learner outcomes
Predict the wavelength of visible light absorbed by a chromophore by visual inspection.
Verify, using a colorimeter and color wheel that wavelengths of light that are complementary are reflected and absorbed by a substance.
III. Resources, materials and supplies needed
Blue, green, yellow Rit®dyes from any store, Spec 20, graph paper, cuvettes ordered from Fisher Scientific.
IV. Supplementary materials, handouts .
Color wheel, instruction for spec 20.
Five-E Organization
Teacher Does Probing Questions Student Does
Engage: Learning Experience(s)
Instructor presents green, blue and yellow solutions and asks student to hypothesize the origin of their colors.
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Critical questions that will establish prior knowledge and create a need to know
What do you see when you look thru a prism?
To what wavelengths do these colors correspond?
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Expected Student Responses/Misconceptions
Wild guesses, general knowledge about what wavelengths are short and which are long.
Know or don’t know that this gives the order of color from longest wavelength to shortest wavelength of light in the visible region. |
Explore: Learning Experience(s)
Students will be provided with solutions of appropriate concentrations to measure their λmax and brief instruction on standardizing the Spec 20.
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Critical questions that will allow you to decide whether students understand or are able to carry out the assigned task (formative)
Can the students standardize the Spec 20 correctly?
Can students make a chart of Absorbance vs. wavelength to determine the wavelength at which each dye absorbs?
Can students use the color wheel to confirm that the wavelength absorbed are the complement of the wavelength reflected. |
Expected Student Responses/Misconceptions
Students will confuse zeroing the instrument with setting transmittance to 100%.
Students will think that they should get a straight line.
Should get this part. |
Explain: Learning Experience(s)
Teacher will lead a discussion of the relationship between energy of EMR and frequency, energy and wavelength.
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Critical questions that will allow you to help students clarify their understanding and introduce information related to concepts to be learned
Can students relate the quantities in appropriate equations to see that they reflect that short wavelength are high frequency and high energy and long wavelength are low frequency and low energy. |
Expected Student Responses/Misconceptions
Short wavelength EMR are low energy because it is counterintuitive that short wavelengths correspond to high energy. Conversely for long wavelengths |
Extend / Elaborate: Learning Experience(s)
Students will be asked to predict the wavelengths absorbed by new solutions of different color.
Students will be asked to work numerical problems converting between wavelength, energy and frequency.
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Critical questions that will allow you to decide whether students can extend conceptual connections in new situations
Can students identify the wavelengths absorbed when 2 colors of dye are mixed? |
Expected Student Responses/Misconceptions
When 2 dyes are mixed they absorb at a wavelength that is intermediate in wavelength of the 2 complementary colors. |
Evaluate: Lesson Objective(s) Learned (WRAP ≠UP at end) -> Summarize
Collect work from extend/evaluate.
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Critical questions that will allow you to decide whether students understood main lesson objectives
Can students manipulate and cancel units appropriately.
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Expected Student Responses/Misconceptions
No units used. Incorrect units in answers.
Units correctly used. |
Percent effort each team member contributed to this lesson plan:
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