Instructional Sequence for Electromagnetic Waves & Technology

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Charlene Simmons
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1 Grade Level: 7 Content and Performance Expectations Essential Question Disciplinary Core Ideas Cross Cutting Concepts Performance Expectation for Assessment Instructional Sequence for Electromagnetic Waves & Technology How are waves used to transfer energy and information? PS4.A Wave Properties A simple wave has a repeating pattern with specific wavelength, frequency, and amplitude. A sound wave needs a medium through which it is transmitted. PS4.B Electromagnetic Radiation When light shines on an object, it is reflected, absorbed, or transmitted through the object, depending on the object s material and the frequency (color) of the light. The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g., air and water, air and glass) where the light path bends. A wave model of light is useful for explaining brightness, color, and the frequency dependent bending of light at a surface between media.however, because light can travel through space, it cannot be a matter wave, like sound or water waves. PS4.C Information Technologies and Instrumentation Digitized signals (sent as wave pulses) are a more reliable way to encode and transmit information. Patterns Graphs and charts can be used to identify patterns in data. Structure and Function Structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used. Structures can be designed to serve particular functions. Influence of Science, Engineering, and Technology on Society and the Natural World Technologies extend the measurement, exploration, modeling, and computational capacity of scientific investigations. Science is a Human Endeavor Advances in technology influence the progress of science and science has influenced advances in technology. MS PS4 1 Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave. [Clarification Statement: Emphasis is on describing waves with both qualitative and quantitative thinking.] [Assessment Boundary: Assessment does not include electromagnetic waves and is limited to standard repeating waves.] MS PS4 2 Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials. [Clarification Statement: Emphasis is on both light and mechanical waves. Examples of models could include drawings, simulations, and written descriptions.] [ Assessment Boundary: Assessment is limited to qualitative applications pertaining to light and mechanical waves. ] MS PS4 3 Integrate qualitative scientific and technical information to support the claim that digitized signals are a more reliable way to encode and transmit information than analog signals. [Clarification Statement: Emphasis is on a basic understanding that waves can be used for communication purposes. Examples could include using fiber optic cable to transmit light pulses, radio wave pulses in wifi devices, and conversion of stored binary patterns to make sound or text on a computer screen.] [Assessment Boundary: Assessment does not include binary counting. Assessment does not include the specific mechanism of any given device.]

2 Learning Progression For the Core Ideas (NGSS Appendix E) Increasing sophistication of student thinking from Kindergarten to Grade 12 Big Idea K PS4.A Wave Properties Sound can make matter vibrate, and vibrating matter can make sound. Waves are regular patterns of motion, which can be made in water by disturbing the surface. Waves of the same type can differ in amplitude and wavelength. Waves can make objects move. A simple wave model has a repeating pattern with a specific wavelength, frequency, and amplitude, and mechanical waves need a medium through which they are transmitted. This model can explain many phenomena including sound and light. Waves can transmit energy. The wavelength and frequency of a wave are related to one another by the speed of the wave, which depends on the type of wave and the medium through which it is passing. Waves can be used to transmit information and energy. PS4.B Electromagnetic Radiation Objects can be seen only when light is available to illuminate them. Object can be seen when light reflected from their surface enters our eyes. The construct of a wave is used to model how light interacts with objects. Both an electromagnetic wave model and a photon model explain features of electromagnetic radiation broadly and describe common applications of electromagnetic radiation. PS4.C Information Technologies & Instrumentation People use devices to send and receive information. Patterns can encode, send, receive and decode information. Waves can be used to transmit digital information. Digitized information is comprised of a pattern of 1s and 0s. Large amounts of information can be stored and shipped around as a result of being digitized. Misconceptions or Difficulties students might have with these ideas (research gathered from: NSTA Nature of Light ebook) Common misconceptions related to Illumination and Sight: Objects are visible because light shines on them, no recognition that light must move between the object and the observer Shadows exist on their own and light pushes them away toward another surface. Shadows are dark reflections of objects Objects are seen because they are bathed in light Light travels from our eyes to objects or light travels to your eyes then to the object Light goes separately to our eyes and the object, there is no link between the two Light is not necessary to see since we can see a little in a dark room We see because we look, it has nothing to do with light A light source and its effects are not separate The eye is an active agent in gathering light, rather than just being a receiver of reflected light Light fills a space ( the room is full of light or light fills a room as water fills a tub) Light travels to an object, lights it up, and stays there Common misconceptions related to Color: Color is a property of an object, and color is not affected by the eye brain system or other receiving system Color is a property of the object, and color is not affected by the illuminating light.

3 The primary colors of light are identical to the primary colors of pigments A white light source produces light made of only one color, it is pure and colorless Sunlight is different from other sources of light because it contains no color When white light passes through a prism, color is added to the light When a colored light illuminates a colored object, the color of the light mixes with the color of the object Sunlight is red, yellow, or orange Common misconceptions related to Wave Movement and Speed: Waves only occur in physical mediums (e.g. water and air) When a wave moves, particles move along with the wave from the point of transmission to the point of reception The effects of light are instantaneous. Light does not travel with a finite speed it travels infinitely fast. Light is associated only with either a source or its effects. Light is not considered to exist independently in space; and hence light is not conceived of as traveling. Light stays on a mirror during reflection. Bright light travels further than dim light. Light travels further at night. Light only travels a short way. Light stops. Common misconceptions related to the Interaction of Light and Matter: Light is reflected away from shiny or smooth surfaces, but light is not reflected from other surfaces. Light always passes straight through a transparent material without changing direction. When an object is viewed through a transparent solid or liquid material the object is seen exactly where it is located. Reflected light is shine or glare it is not something associated with seeing objects. Light can only be absorbed, blocked, or reflected by an object. One object cannot do all three. Common misconceptions about the Electromagnetic Spectrum: Visible light is the only type of light. Gamma rays, X rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves are all very different entities. All parts of the electromagnetic spectrum reach us on Earth. All radiation is harmful. All celestial objects are brightest in visible light. Overarching Focus Question for the Instructional Sequence: Essential Questions from the Framework: How are waves used to transfer energy and information? Lesson Sequence Questions: What are the characteristic properties and behaviors of waves? What do the terms frequency, wavelength, and amplitude describe? What happens when the frequency, wavelength, or amplitude of a wave change? Can sound travel anywhere? Why or why not? What is light? How does a wave model explain brightness, color, and (frequency dependent) bending of light? How can one explain the varied effects that involve light? What happens when light shines on an object or different materials? (Reflected, absorbed, transmitted) What path does light take through different mediums and at their intersection? What other forms of electromagnetic radiation are there?

4 What is the electromagnetic spectrum? How do different parts of the EM spectrum interact with various materials? How are instruments that transmit and detect waves used to extend human senses? Sequence Overview: The instructional sequence for this unit is broken into three major phases, with each phase corresponding to a Disciplinary Core Idea from the NGSS. In phase one, students explore the characteristics of waves by physically generating and observing waves. In phase two, students are introduced to wave concept of light and explore how the features of waves explain color and interactions with different medium. Instructional Sequence Design: 1 Phase 1: Characteristics and Properties of Waves Beginning Observe and describe videos of waves in water. Middle Describe common features or patterns in waves. Create standing waves with a wave tank and make wave prints Developing and using models Make predictions of the relationship between frequency, wavelength, height (amplitude), period and speed Obtaining, evaluating and communicating information Test predictions using wave tanks End 1 See Kaupp et al (October 2013) Catching Waves: Making Wave Prints to Introduce Wave Properties. Science Scope, Vol. 37(2), p

5 Identify relationships between wave features from group data Use mathematics and computation thinking Use formulas to demonstrate and calculate the relationship between wave features Asking questions and defining problems Phase 2: Light and the Electromagnetic Spectrum Beginning Middle End Test which materials transmit or block different types of EM radiation 2 Phase 3: Wave Technologies Beginning What will the teacher plan? What will the teacher do? What will the students do? S&E Practices intentionally 2 See Tretter (October 2014) Teaching Electromagnetic Waves Used in Communication Technologies. Science Scope, Vol. 38(2), p.78 86

6 Middle End

SNC 2PI Optics Unit Review /95 Name:

SNC 2PI Optics Unit Review /95 Name: Part 1: True or False Indicate in the space provided if the statement is true (T) or false(f) [15] 1. Light is a form of energy 2. Shadows are proof that light travels