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Can You See the Light?
Grades: 5-8
Author: Joyce Brumberger
Source: Original
Abstract
Students will learn through design and implementation of their own experiments about the transmission of light energy. Vocabulary terms such as transparent, translucent, and opaque are introduced and explored through hands-on exploration.
Objectives
What should students know as a result of this lesson?
- definition of the terms transparent, translucent, and opaque
- difference between transparent and translucent
What should the students be able to do as a result of this lesson?
- provide examples of materials that are translucent, transparent, and opaque
- design and implement an experiment
- write a procedure for an experiment
- collect and record data
- analyze data and draw conclusions from it
Materials
- Jars of soap blowing bubbles
- Colored filters - colored paddles are available through Educational Innovations, Inc. 888-912-7474; Nasco, Inc. 800-558-9595
- Colored cellophane wrap
- Flashlight (optional)
- Water
- Baby food jars or other small containers
- Thermometers (2/group)
- Heat lamps
Squares of materials that are the same size. Examples are:
- Lucite
- Polystyrene - clear plastic food packaging boxes (#6 recycle code)
- Plastic milk jug
- Plastic laundry detergent bottle
- Plastic bleach bottle
- Clear food wrap film (for example, Saran WrapTM )
- Wax paper
- Overhead transparency
- Plastic grocery bag
- White fabric cloth
- Black fabric cloth
- Tissue paper
- Disposable food containers with lids (for example, ZiplockTM)
- Colored paper
- Cellophane wrap
- Wood
- Mirror
- Aluminum foil
Procedures
Engagement
If possible, plan to conduct this activity outside.
- Working in groups of five, ask one participant to blow bubbles while the others observe them through four different colored filters.
- Ask students with the filters to record the color of the filter and what colors were visible on the bubble through the filter.
- Tell students to change roles until everyone has had an opportunity to blow bubbles and look through each of the filters.
- In a large group, ask students what colors were visible through each of the filters.
Assessment: Assess students understanding through oral explanations and written observations and drawings.
Exploration
Working with partners or small groups, ask students to look at a light source with the various materials provided. Allow them to use their own vocabulary and record their responses as to how much light is transmitted through the materials. The light source could be a flashlight or looking up at ceiling lights.
Assessment: Assess students understanding through oral explanations and written observations and drawings.
Explanation
Provide formal definitions of key terms.
- What is the term for a material that you can see through clearly?
Answers may vary. The term is transparent.
- Ask students for examples of transparent materials that they used here as well as any additional examples.
Examples used here were the Lucite and polystyrene plastic. Additional examples will vary
- What is the term for a material that lets light through but not clearly?
Answers may vary. The term is translucent.
- Ask students for examples of translucent materials that they used here as well as any additional examples.
An example used here was the milk jug plastic. Additional examples will vary.
- What is the term for a material that does not let light through?
Answers may vary. The term is opaque.
- Ask students for examples of opaque materials that they used here as well as any additional examples.
Examples of opaque materials used here were the plastic from the detergent bottle, mirror, white cloth, and wood. Additional examples will vary.
- Ask students what happens to light energy when it interacts with opaque materials?
Light can be reflected, like the mirror, it can be absorbed like the wood, or it can be both, like the white cloth.
- Tell students to look at the list of opaque materials discussed previously and ask them to determine if they reflect light, absorb light, or both.
(Answers will vary)
Assessment: Students' responses to key concepts and their responses to additional examples.
Elaboration
- Tell students that as the cost of energy rises, the need for alternative sources of energy, such as solar energy, are becoming very attractive.
- Divide students into groups of four. Based on the research they just conducted, challenge them to design an experiment in which they may compare TWO of the materials they just explored to determine which would be more effective in heating a container of water using solar energy.
- Tell students that they will all be given equal amounts of water so that their collective data can be shared at the end of experimentation.
- Tell students to formulate a testable question, hypothesis, and write a list of materials and step-by-step procedure as learned in the One Plus One Makes New Lesson. Accept all reasonable work and allow students to conduct their experiments. Generally, materials that are transparent will allow the electromagnetic radiation to pass through them, but not necessarily back out.
- Ask students to analyze their data and draw a conclusion.
- Ask a spokesperson from each group to report their findings to the group as a whole. Based on the data provided, ask them to organize the materials in order from best to worst with regard to their ability to heat water. (Transparent materials will likely have the best performance)
- Ask students what purpose they would suggest for materials that are translucent and opaque when thinking about energy conservation. (Translucent materials are useful for allowing some light to penetrate through but would be helpful in reducing accumulated heat.)
Assessment: Written or oral responses to Steps 5-7 above.
Prerequisites
Minimal math skills - multiplication and division
Use of a calculator
Best Teaching Practices
- Learning Cycle
- Science Process Skills
- Inquiry
Alignment with Standards
NGSS Standards:
- MS-PS4-2 Develop and use a model to describe that waves are reflected, absorbed, and transmitted through various materials.
Common Core Standards:
- RST.6-8.3 Follow preciesly a multistep procedure when carrying our experiments, taking measurements, or performing technical tasks.
- WHST.6-8.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- WHST.6-8.9 Draw evidence from informational texts to support analysis, reflection, and research.
National Standards:
- Content Standard A: 5-8 Science as Inquiry
- Content Standard B: 5-8 Physical Science
- Content Standard G: 5-8 History and Nature of Science
Ohio Standards:
- Grades 6-8 Physical Science Benchmark C
- Grades 6-8 Scientific Ways of Knowing Benchmark A and B
Content Knowledge
Light is a type of electromagnetic radiation which travels in the form of waves. Most natural light comes from the sun and travels though the vacuum of space transferring potential energy to kinetic energy when the wave interacts with a medium that causes the material to move. Waves behave in predictable ways and have measurable properties.
When light travels through a medium it can be reflected, refracted, absorbed, and scattered. Different materials transmit light to different degrees and are classified based on their transmission levels. Materials that allow light to transmit through them are considered transparent. These materials however may be transparent to some wavelengths of light and not others. Colored filters are examples of such materials. Translucent materials allow some light to transfer through them, but also scatter light in different directions. When a material is opaque, it does not allow light to transfer through either by way of reflection and /or absorption.
When light passes through a transparent material and hits another surface, the wavelength is altered. As a result, much of the energy cannot transmit back through the transparent material and is converted to heat. This is why a car interior heats up on a hot day when the car is sitting in the mall parking lot.
Additional References:
Safety
Use care not to get soap bubbles in the eyes.
Applications
As the price of crude oil continues to increase, the public is becoming more aware of the need to reduce its dependency on oil and turn its attention towards alternative energy sources and increased conservation. To conserve energy, more and more companies and institutions are looking for ways to "Go Green". Buildings are being structurally designed to minimize fossil fuel consumption and provide a comfortable and esthetic interior environment. As a result, materials that have been used in the past are either being enhanced or used in new ways to meet conservation goals.
It is necessary to first understand the basic properties of these materials before proper application or enhancement can be made. This is done through exploration and experimentation.
Assessment
Ongoing throughout learning cycle
Other Considerations
Grouping Suggestions: Try to insure that all students have participated and expressed their ideas either verbally or through written comments. When working in pairs or groups try to make the groups as heterogeneous as possible being sensitive to specific needs of individuals.
Pacing/Suggested Time:
- Engagement - 20 minutes
- Exploration - 20 minutes
- Elaboration - 15 minutes
- Explanation - Two 40 minute sessions
Printable PDF Worksheets
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