This student is looking at many colors on his computer screen. What he is actually seeing, however, are combinations of only three colors of light.

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• This student is looking at many colors on his
  computer screen. What he is actually seeing,
  however, are combinations of only three colors of
  light.

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Separating White Light Into Colors
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Separating White Light Into Colors

• Sunlight is made up of all the colors of the
  visible spectrum. A prism separates white light
  into a visible spectrum.
• When red light, with its longer wavelength,
  enters a glass prism, it slows down the least of
  all the colors.
• Red light is bent the least.
• Violet light is bent the most.

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Separating White Light Into Colors

• The process in which white light separates into
  colors is called dispersion. A rainbow forms when
  droplets of water in the air act like prisms.
• When light enters a raindrop, it slows down and
  refracts. Then it reflects off the far inner
  surface of the raindrop.
• It refracts again as it exits the raindrop,
  speeds up, and travels back toward the source of
  the light.

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Separating White Light Into Colors

1. The shorter wavelengths are bent more than the
   longer wavelengths. The colors are separated.
2. Water droplets separate the colors of sunlight,
   producing a rainbow.

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The Colors of Objects
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The Colors of Objects

• An objects color is the color of light that
  reaches your eye when you look at the object.
• Sunlight contains all the colors of the visible
  spectrum.
• A red car in sunlight reflects mostly red light.
• Most of the rest of the light is absorbed at the
  surface of the paint.

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The Colors of Objects

• What happens if you change the color of the light
  shining on an object?
• Only the colors that are in the light can be
  reflected.

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The Colors of Objects

• Under white light, the pots appear white, green,
  yellow, red, and blue. The pots appear to be
  different colors when viewed in different colors
  of light, depending on what light is reflected.

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The Colors of Objects

• Under white light, the pots appear white, green,
  yellow, red, and blue. The pots appear to be
  different colors when viewed in different colors
  of light, depending on what light is reflected.

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The Colors of Objects

• Under white light, the pots appear white, green,
  yellow, red, and blue. The pots appear to be
  different colors when viewed in different colors
  of light, depending on what light is reflected.

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The Colors of Objects

• Under white light, the pots appear white, green,
  yellow, red, and blue. The pots appear to be
  different colors when viewed in different colors
  of light, depending on what light is reflected.

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Mixing Colors of Light
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Mixing Colors of Light

• The three primary colors of light are red, green,
  and blue. When any two primary colors combine, a
  secondary color is formed.

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The Colors of Objects

• If more than one color of light is reflected from
  a surface, the colors of light mix. When colors
  of light mix, they add to form a new color.
• Each secondary color of light is a combination of
  two primary colors. The secondary colors of light
  are cyan, yellow, and magenta.

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The Colors of Objects

• If you add a primary color to the proper
  secondary color, you will get white light.
• Two colors of light that combine to form white
  light are complementary colors of light.
• A complementary color pair is a combination of
  one primary color and one secondary color.

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Mixing Pigments
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Mixing Pigments

• A pigment is a material that absorbs some colors
  of light and reflects other colors.
• Paints, inks, photographs, and dyes get their
  colors from pigments.
• Color printers and photocopiers use three
  colorscyan, magenta, and yellowplus black.
• You can mix varying amounts of these primary
  pigment colors to make almost any other color.

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Mixing Pigments

• Each pigment reflects one or more colors. As
  pigments are mixed together, more colors are
  absorbed, and fewer colors are reflected.
• When two or more pigments are mixed together, the
  colors absorbed by each pigment are subtracted
  out of the light that strikes the mixture.

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Mixing Pigments

• Any two colors of pigments that combine to make
  black pigment are complementary colors of
  pigments.
• Cyan and magenta combine to form blue.
• Cyan and yellow combine to form green.
• Yellow and magenta combine to form red.
• The secondary colors of pigments are red, green,
  and blue.

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Mixing Pigments

• The three primary colors of pigments are cyan,
  yellow, and magenta. When the three primary
  colors of pigments are combined, the secondary
  colors of pigments are formed.

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Assessment Questions

• A prism separates white light into the visible
  spectrum because
• longer wavelengths are absorbed more than shorter
  wavelengths.
• shorter wavelengths refract more than longer
  wavelengths.
• shorter wavelengths reflect more than longer
  wavelengths.
• longer wavelengths experience more interference.

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Assessment Questions

• A prism separates white light into the visible
  spectrum because
• longer wavelengths are absorbed more than shorter
  wavelengths.
• shorter wavelengths refract more than longer
  wavelengths.
• shorter wavelengths reflect more than longer
  wavelengths.
• longer wavelengths experience more
  interference.ANS B

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Assessment Questions

• The color of an object depends on what the object
  is made of and on
• the intensity of light that strikes the object.
• the color of light that strikes the object.
• the direction of the light that strikes the
  object.
• the speed of the light that strikes the object.

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Assessment Questions

• The color of an object depends on what the object
  is made of and on
• the intensity of light that strikes the object.
• the color of light that strikes the object.
• the direction of the light that strikes the
  object.
• the speed of the light that strikes the
  object.ANS B

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Assessment Questions

• Which of these colors is one of the primary
  colors of light?
• green
• magenta
• yellow
• white

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Assessment Questions

• Which of these colors is one of the primary
  colors of light?
• green
• magenta
• yellow
• whiteANS A