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Date:
Nature of Light Unit Test Review Sheet
Lesson 1: What Is Light?
1. Know the characteristics of light
Lesson 2: Where does light come from?
Key Terms: Energy Transformations, Electromagnetic (Light) Energy, Thermal (Heat) Energy, Luminous,
and Nonluminous
1. What is an energy transformation?
- An energy transformation is when one form of energy is changed into another form of
energy.
2. What is the energy transformation occurring in a lightbulb? (Show the direction of the energy
transformation).
- Electrical energy to electromagnetic (light) energy and thermal (heat) energy
3. What is a luminous object and a non-luminous object? Give an example of each?
- Luminous objects produce light. Examples= Light bulb, Candle, Sun, Bioluminescent
organisms, etc.
- Non-luminous objects do not produce their own light. Examples= Moon, Mirror, etc.
Lesson 3: How Does Light Travel?
Key Terms: Light Year
1. Does light travel in straight lines? How do you know?
- Yes, light does travel in straight lines. During Inquiry 3.1, when the rubber tubing was bent
light did not pass through, but when it was straight light did pass through.
2. If light is invisible as it travels, what do you need to do to detect light?
- You need a form of matter to intercept the path of light and reflect it back to the observer’s
eyes.
3. How long does it take for the sunlight to reach Earth? (Use the diagram on page 41 in the
textbook to assist you in answering the question.)
- 8.3 minutes
Lesson 4: Blocking the Light
Key Terms: Shadow, Transparent, Translucent, and Opaque
1. What is a transparent, translucent, and opaque object? Give an example of each.
- Transparent objects allow all light to pass through and can be clearly see through.
Examples= Water, Clear glass, Color filters, etc.
- Translucent objects allow some light to pass through. Examples= Frosted glass, wax paper,
etc.
- Opaque objects do not let light pass through and cannot be clearly seen through.
Examples= Wood, Steel, etc.
2. What is the relationship between the size of a shadow on a screen and the distance of the
screen from the object that produces the shadow?
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- When an object is closer to a screen, the shadow size decreases.
- When an object is further away from a screen, the shadow size increases.
3. What is the relationship between the size of a shadow on a screen and the distance of the
object from the light source?
- When an object is closer to a light source, the shadow size increases.
- When an object is further away from a light source, the shadow size decreases.
Lesson 5: Where Does Color Come From?
Key Terms: Prism, Refraction, and Visible Spectrum
1. How does a prism split white light into the visible spectrum?
- A prism refracts white light into the colors of the visible spectrum.
2. What is the order of colors in the visible spectrum from longest to shortest wavelength?
- Red, orange, yellow, green, blue, indigo, and violet (ROY G BIV).
3. What color has the most energy and frequency? What color has the least energy and
frequency?
- Violet has the most energy and highest frequency. Red has the least energy and lowest
frequency.
4. What did Sir Isaac Newton prove about white light?
- Sir Isaac Newton proved that white light is not pure, white light is made up of a mixture of
colors, and glass doesn’t add colors to light.
Lesson 6: Color, Wavelength, and the Wider Electromagnetic Spectrum
Key Terms: Wavelength, Crest, Trough, Frequency, Amplitude, and Electromagnetic Spectrum
1. What is the relationship between wavelength, frequency, and energy?
- When wavelength increases (gets longer), frequency and energy decrease.
- When wavelength decreases (gets shorter), frequency and energy increase.
2. What are the parts of a wave?
- Crest= top of a wave
- Trough= bottom of a wave
- Wavelength= distance from two crests or two troughs
- Amplitude= Midpoint of a wave to the top or bottom of a wave
3. How is wavelength measured?
- Wavelength is the distance between two crests or two troughs.
Lesson 8 and 9: Looking at Colors and Colored Lights
Key Terms: Additive and Subtractive Color Mixing
1. What is additive and subtractive color mixing?
- Colored light can be mixed to make new colors. This is called additive color mixing.
- Color mixing using inks, paints, or filters laid on top of one another removes colors form
white light. This is called subtractive color mixing.
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2. How do the primary and secondary colors for additive and subtractive color mixing mix?
Subtractive Color Mixing
Additive Color Mixing
Cyan and Magenta= Blue
Red and Blue= Magenta
Magenta and Yellow= Red
Red and Green= Yellow
Cyan and Yellow= Green
Green and Blue= Cyan
Cyan, Yellow, and Magenta= Black
Red, Blue, and Green= White
3. When John looked at a red object through a green filter. What color did the object appear?
Why do color filters change the color of an object viewed through a filter?
- The object appear black, because the color filter absorbs the red wavelengths of light
being reflected from the object.
4. Why does a leaf appear green in white light?
- A leaf appears green in white light, because it absorbs all the colors of the visible
spectrum, except green, which it reflects back to the observer’s eyes.
5. Why does an object appear white in white light?
- The object appears white, because it reflects all of the colors of the visible spectrum.
6. Why does an object appear black in white light?
- The object appears black, because it absorbs all the colors of the visible spectrum.
Lesson 10: How is Light Reflected?
Key Terms: Reflection
1. What is the law of reflection?
- The law of reflection states that the angle of incidence is always equal to the angle of
reflection.
Lesson 11: Introducing Refraction
Key Terms: Refraction
1. What is refraction and how does it occur?
- Refraction occurs when light travels from one material to another and slows down. For
example, when light travels from air to glass or glass to air.