Mastery. Chapter Content. What is light? CHAPTER 11 LESSON 1 C A

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1 Chapter Content Mastery What is light? LESSON 1 Directions: Use the letters on the diagram to identify the parts of the wave listed below. Write the correct letters on the line provided. 1. amplitude 2. crest 3. trough 4. wavelength D C A B Directions: Circle the term in parentheses that makes each statement true. 5. The number of times a point on a wave moves from its highest point to its lowest point and back again in one second is the wave s (frequency/vibration). 6. The substance through which a wave moves is called the wave s (amplitude/medium). 7. Light is a(n) (compressional/electromagnetic) wave. 8. The range of electromagnetic waves human eyes can detect is called the visible light (spectrum/ medium). 9. A light (ray/arrow) is a narrow beam of light that travels in a straight line. 10. Light waves carry (energy/atoms) from place to place. 11. When you divide 1 by the (period/wavelength) of a wave, the resulting number is the frequency of the wave. 12. The closer together the crests of a wave are, the higher the wave s (frequency/wavelength). 12 The Eye and Light

2 Chapter Content Mastery Light and Matter LESSON 2 Directions: Match the terms in Column I with the phrases in Column II. Write the letter of the correct phrase in the blank to the left. Column I 1. transmission 2. opaque 3. refraction 4. prism 5. translucent 6. absorption 7. transparent 8. scattering 9. primary colors of light Column II A. when a light ray bends as it moves from one material into another B. red, green, and blue light C. a piece of transparent glass or plastic that is usually shaped like a wedge D. describes a medium that prevents all light rays from passing through it E. when a material absorbs light, and then reemits the light in different directions F. describes a medium that transmits nearly all the light rays that hit it G. describes a medium that only allows some of the light rays to pass through it H. the process of converting light energy into thermal energy when light rays strike an atom I. when light rays strike a material and are transferred through the material Directions: Using complete sentences, answer each question and respond to each statement below in the space provided. 10. What is the law of reflection? 11. Explain why a blade of grass appears to be green but a brick appears to be red. The Eye and Light 13

3 Chapter Content Mastery Using Lenses LESSON 3 Directions: Use the clues below to complete the crossword puzzle Across in a lens, an imaginary line that would pass through the center of the lens, perpendicular to its curved surface(s) 6. a telescope that uses a mirror to collect light emitted by distant or faint objects 8. an optical instrument that makes objects that are far away look closer 9. the point where all of the beams of light leaving a lens converge 10. the smaller lens in a refracting telescope, located nearer to the viewer s eye 11. the likeness of something produced by an optical device such as a lens 12. a lens that bulges outward 11 Down 1. a tool that uses lenses to focus light and create useful images 2. the distance from the center of a lens to its focal point 4. an optical instrument that uses two convex lenses to allow you to see very small objects 5. a curved, transparent object used to refract light 7. the large lens at the end of a refracting telescope, located farther from the viewer s eye 14 The Eye and Light

4 Chapter Content Mastery The Eye and Vision LESSON 4 Directions: Use the following terms to complete the sentences below. cones cornea farsighted iris nearsighted pigment pupil rhodopsin rods sclera 1. The is a clear area of the sclera, and it is a convex lens that causes light rays to converge as they enter the eye. 2. A person who cannot see distant objects clearly is. 3. are cells in the retina that detect all wavelengths of light and work best in dim light. 4. A colored material used to change the color of something else is a(n). 5. The is the colored part of an eye behind the cornea that expands and contracts depending on light conditions. 6. A person who is cannot see close objects clearly. 7. A molecule called contained in rod cells changes its chemical form when light hits it, generating an electrical signal sent to the brain through the optic nerve. 8. The outer layer of an eye is the. 9. The is the dark opening into the interior of the eye that allows light rays to enter the eye. 10. The light-sensitive cells in the retina that detect different colors of light are called. The Eye and Light 15

5 Reinforcement What is light? LESSON 1 Directions: Write the term that matches each description below in the spaces provided. The letters in the darker boxes will spell the answer to question a type of wave that can travel through empty space as well as through matter 2. a narrow beam of light that travels in a straight line 3. a type of electromagnetic wave that you can see and that transfers energy 4. the time it takes a point on a wave to move from its lowest point to its highest point and back to its lowest point again 5. the distance between a wave s crest or trough and its resting position 6. the substance through which a wave moves 7. the entire range of electromagnetic waves of different wavelengths 8. the lowest points on a wave 9. the highest points on a wave 10. the range of electromagnetic waves that human eyes can detect 11. The distance between two crests is the of a wave. 20 The Eye and Light

6 Reinforcement Light and Matter LESSON 2 Directions: Circle the term that correctly completes each sentence. 1. A medium that prevents all light rays from passing through it is called (translucent/opaque). 2. A piece of transparent glass or plastic that is usually shaped like a wedge is called a (prism/mirror). 3. (Transmission/Absorption) occurs when light rays strike a material and are transferred through the material in a cycle of absorption and reemission. 4. The process of a light ray bending when it moves from one medium into another is called (scattering/refraction). 5. A (transparent/opaque) medium is one that transmits nearly all the light rays that hit it. 6. It is called (scattering/absorption) when light energy from light rays is converted into thermal energy when hitting an atom. 7. (Translucent/Transparent) materials allow only some of the light rays that hit them to pass through. Directions: Answer each question or respond to each statement on the lines provided. 8. What might cause the speed of light to vary? 9. Explain how a white piece of paper reflects light differently from a mirror. 10. If you see a red ball, what color(s) of light enter(s) your eye from the ball? What color(s) does the ball reflect? What color(s) does the ball absorb? 11. What are the primary colors of light? Why are they called primary colors? The Eye and Light 21

7 Reinforcement Using Lenses LESSON 3 Directions: Write the name of each optical instrument telescope, microscope, or camera that matches each description below. If a description matches more than one instrument, be sure to list each instrument that fits the description. 1. has two lenses called the eyepiece lens and objective lens 2. allows a person to see faraway objects more clearly 3. can be made with a mirror instead of a lens in order to collect more light 4. moves a lens to focus an image sharply on a piece of film or a digital sensor 5. collects more light than a human eye can to create a useful image 6. uses a combination of lenses and a tube to enlarge objects 7. allows a person to see small objects more clearly Directions: Complete each sentence below with a term from the lesson. 8. A(n) is a curved, transparent object used to refract light. 9. The distance between the center of a lens and its focal point is the of the lens. 10. A(n) lens always forms an image that is on the same side of the lens as the original object and right-side up. 11. A convex lens has at least one side that. 12. Light travels more in a lens than it does in air. 13. telescopes are sometimes used to see distant or faint objects because it is easier to make and support large mirrors than it is to make and support large lenses. 22 The Eye and Light

8 Reinforcement The Eye and Vision LESSON 4 Directions: Label the diagram of the human eye shown below Directions: Answer each question or respond to each statement on the lines provided. 7. Explain how the lens is used to allow a person to see both nearby and faraway objects clearly. 8. What is the iris, what does it have to do with the pupil, and how would the iris and pupil change if you walked from a dark room into bright sunlight? 9. Name the two types of light-sensitive cells that are present in the retina, and briefly explain how they are different. The Eye and Light 23

9 Content Vocabulary The Eye and Light Directions: Match each term with its definition by writing the correct letter on the line next to the definition. 1. the outer layer of the eye A. absorption 2. when a light ray bends, or changes direction, when it moves from one material into another 3. an optical instrument that makes objects that are far away look closer 4. the point where all of the beams of light leaving a lens converge 5. a term for a medium that transmits nearly all the light rays that hit it B. farsighted C. transparent D. lens E. translucent F. refraction G. sclera 6. the distance between any two peaks or any two troughs of a wave 7. a term used to describe a person who cannot see close objects clearly 8. a term used to describe a person who cannot see faraway objects clearly 9. a narrow beam of light that travels in a straight line 10. a curved, transparent object used to refract light 11. a word used to describe a medium that only allows some of the light rays that hit it to pass through it 12. the process of converting light energy into thermal energy when light rays strike an atom 13. the number of times a point on a wave moves from its crest to its trough and back to its crest in one second. H. light ray I. focal point J. wavelength K. telescope L. frequency M. nearsighted The Eye and Light 29

10 Content Vocabulary CONTINUED Directions: Fill in each blank with the proper term. convex lens cornea electromagnetic spectrum focal length iris law of reflection medium microscope pigment pupil retina scattering 14. The distance from the center of a lens to its focal point is the lens s. 15. Another name for the entire range of electromagnetic waves of different wavelengths is the. 16. The is the part of the eye that is colored and behind the cornea. 17. The effect called happens when a material absorbs light and then reemits the light in different directions. 18. Paint is a, or a colored material used to change the color of something else. 19. The sheet of light-sensitive cells in the back of the eye is called the. 20. A(n) is an optical instrument that uses two convex lenses to allow you to see very small objects. 21. The clear area of the sclera that is a convex lens and causes light rays to converge as they enter the eye is also known as the. 22. The is the substance through which a wave moves. 23. The states that when a light ray is reflected from a surface, the light ray s angle of incidence equals its angle of reflection. 24. A lens that bulges outward is a(n). 25. The is the dark opening into the interior of an eye that allows light rays to enter the eye. 30 The Eye and Light

11 Chapter Review Part A. Vocabulary Review The Eye and Light Directions: Identify the term in Column II that matches each definition in Column I. Write the letter of the correct term in the blank at the left. Column I 1. when a light ray bends, or changes direction, when it moves from one material into another 2. the point where all of the beams of light leaving a lens converge Column II A. lens B. refraction C. wavelength 3. the distance between any two peaks or any two troughs of a wave 4. a curved, transparent object used to refract light 5. the number of times a point on a wave moves from its crest to its trough and back to its crest in one second D. frequency E. focal point F. iris G. cornea H. scattering 6. another name for the entire range of electromagnetic waves of different wavelengths 7. the part of the eye that is colored and located behind the cornea 8. when a material absorbs light and then reemits the light in different directions 9. a colored material used to change the color of something else 10. the sheet of light-sensitive cells in the back of the eye 11. the clear area of the sclera that is a convex lens and causes light rays to converge as they enter the eye 12. the substance through which a wave moves I. pupil J. retina K. electromagnetic spectrum L. pigment M. medium 13. the dark opening into the interior of an eye that allows light rays to enter the eye The Eye and Light 31

12 Chapter Review CONTINUED Part B. Concept Review Directions: Write the term for each part of the wave in the diagram below next to the corresponding number Directions: Answer each question in the space provided. 5. Contrast the wavelength, period, and frequency of a wave. 6. Predict what you would see if you used a prism to refract white light. 7. Formulate a written description of how the eye works, using the terms cornea, pupil, iris, retina, and optic nerve. 32 The Eye and Light

13 Chapter Outline Lesson 1: What is light? A. Light Transfers Energy The Eye and Light 1. A(n) is a narrow beam of light that travels in a straight line. 2. Light carry energy from place to place. a. The of a wave are called crests. The lowest points are called. b. A(n) is the distance between any two peaks or any two troughs of a wave. c. The of a wave is the distance from a crest or trough of the wave to the resting position. d. The time that it takes a point on the wave to move from its highest point to its lowest point and back again is the of the wave. e. The of a wave is the number of times that a point on the wave moves from its highest point to its lowest point and back again in one second. It is equal to 1 divided by the period of the wave. f. When the frequency of a wave, the wavelength increases. When the frequency increases, the wavelength. 3. Light is a type of wave. a. The substance through which a wave moves is called its. b. Light is an electromagnetic wave, which means it can move through, as well as through other mediums. B. The Electromagnetic Spectrum 1. The entire range of electromagnetic waves of different wavelengths is called the. 2. The range of electromagnetic waves that human eyes can detect is the. 42 The Eye and Light

14 Chapter Outline CONTINUED Lesson 2: Light and Matter A. The Interaction of Light and Matter 1. When light rays hit, they can be absorbed, be reflected, or pass right through the material. 2. is the process of converting light energy into thermal energy when light rays hit an atom and light s energy is transferred to the atom. 3. occurs when light rays strike a material and are transferred through the material in a cycle of absorption and reemission. 4. The process of a material absorbing light and then reemitting light in different directions is called. 5. Light behaves differently depending on the it hits. a. A(n) material is one that prevents all light rays from passing through the material. b. A medium that transmits nearly all the light rays that hit it is called. c. mediums allow only some light rays to pass through them. 6. In a(n), light travels at about 300,000 km/s. In other transparent mediums, it travels at different, slower speeds. B. Refraction 1. occurs when a light ray bends, or changes directions, when it moves from one material into another. 2. When light rays pass between two transparent materials in which the speed of light differs, the change in the speed of light causes light rays to. 3. Refraction affects different of the visible spectrum differently. a. A is a piece of transparent glass or plastic that usually is shaped like a wedge. b. The different colors, or wavelengths, of light refract by different amounts when they pass through a prism. 4. Mixing multiple colors of light can create white and other different colors. With the color can be made. colors of light, red, green, and blue light, almost any other The Eye and Light 43

15 Chapter Outline CONTINUED C. Reflection 1. The law of reflection states that when a light ray is reflected from a surface, the equals the angle of reflection. 2. When light rays hit an uneven surface, like a sheet of paper, each ray obeys the slightly different direction., but because the surface is uneven, each ray reflects in a 3. Colored objects appear to have a particular color because they absorb all other your eye. of light, and only the color you see is reflected from the object to D. Light, Matter, and Atomic Structure 1. All objects that human eyes can see either reflect light or are of light. 2. The types of light coming from the object depend on the and Lesson 3: Using Lenses in the object. A. What is a lens? 1. A is a curved, transparent object used to refract light. 2. Every lens has at least one surface. B. Convex Lenses 1. A lens that bulges outward is called a. 2. A convex lens causes light rays to. 3. All of the light rays that pass through a convex lens come together to one. a. The of a convex lens is the point on the major axis of the lens at which all beams of light traveling through and away from the lens converge. b. The distance from the center of the lens to the focal point is called the. 44 The Eye and Light

16 Chapter Outline CONTINUED 4. The image of an object formed by a convex lens depends on the position of the object in relation to the of the lens. C. Optical Instruments 1. A camera is focused by changing the distance between the camera s image is formed. and its film so that the film is at the exact location where the 2. An optical is an optical instrument that uses two convex lenses to allow you to see small objects. 3. Refracting telescopes use two lenses. a. A is an optical instrument that makes objects that are far away look closer. b. A refracting telescope uses two convex lenses, called the eyepiece and objective lenses, at either end of a to enlarge the images of distant objects. 4. Because it is easier to collect a large amount of light with a mirror than a lens, most large telescopes used to view faint and distant objects use light and are called reflecting telescopes. to collect D. Lenses as Tools 1. Lenses make use of refraction to form. 2. Lenses can be used to collect and focus from objects that wouldn t otherwise be visible. Lesson 4: The Eye and Vision A. How the Eye Forms an Image 1. The outer layer of the eye, which has a clear front part, is called the. 2. The is the clear area of the sclera and is also a convex lens that causes light rays to converge as they enter the eye. 3. The is the dark opening into the interior of the eye. The Eye and Light 45

17 Chapter Outline CONTINUED 4. The colored part of the eye surrounding the pupil is called the. The iris expands and contracts, making the This controls the amount of that enters the eye. smaller or larger. 5. Muscles attached to the lens change the shape of the lens to focus sharp images of objects at different distances on the of the eye. 6. The retina sends signals to the. a. The sheet of light-sensitive cells in the back of the eye is called the. b., which work better in dim light, are one type of cell that make up the retina. B. Seeing Color 1. The three types of cone cells in the retina are most sensitive to red,, and blue light respectively. 2. The brain responds to signals from the different types of cone cells at the same time by mixing the colors to form other colors. 3. In addition to the primary colors of light, there are also three primary pigment colors. a. A is a colored material used to change the color of something else. b. The primary colors of pigments are, cyan, and yellow. 4. Color printing in magazines is done by placing tiny dots of the three colors of pigments along with tiny human eye to distinguish clearly. C. Common Vision Problems dots that are too small for the 1. Glasses and contact lenses can correct two common problems called nearsightedness and farsightedness. 46 The Eye and Light

18 Chapter Outline CONTINUED a. A person who is cannot see faraway objects clearly and can often wear glasses with a faraway objects sharply on the retina. lens to help focus the images of b. Someone who is has a hard time seeing close objects and can wear glasses with convex lenses to help correct his or her vision. 2. Some people and animals cannot distinguish between different of light. a. People who have a difficult time telling the difference between and objects have a red-green color deficiency. b. Red-green color deficiency is more common in the gender. D. The Eye and Sight 1. The eye is a complex light-detecting. 2. The cells of the retina send signals to the brain. The Eye and Light 47