Spectrum
For sunlight and other white light, the spread of colors seen when the light s passed through a prism or diffraction grating. In general, the spread of radiation by frequency, so that each frequency appears at a different position.
White Light
Light, such as sunlight, that is a combination of all the colors. Under white light, white objects appear white and colored objects appear in their individual colors.
Pigment
A material that selectively absorbs colored light.
Additive Primary Colors
Red blue and green light. These colors when added produce white light.
Complementary Colors
Two colors of light beams that when added together appear white.
Subtractive Primary Colors
The colors of magneta, yellow, and cyan. These are the three colors most useful in color mixing by subtraction.
Scattering
A process in which sound or light is absorbed and re-emitted in all directions.
Excited State
A state with greater energy than an atom's lowest state.
Spectroscope
An instrument used to separate the light from a hot gas or other light source into its constituent frequencies.
Line Spectrum
A pattern of distinct lines of color corresponding to particular wave lengths, that are seen in a spectroscope when a hot gas is viewed.
Origin of Color
Origin of color is from the frequencies of light emitted or reflected by things.
Perception of color depends on....
They eye-brain system, the eye of the be holder.
Newton's First Attempt
A narrow beam of light passed through a prism which caused the white light to separate into the colors of the rainbow.
Color Order of the Spectrum (from low freq. to high)
Red, Orange, Yellow, Green, Blue, Violet
Black and White (real colors?)
Not real colors. White is a combination of all colors and black is the absence of color
Light in Transparent Materials
Light that is not absorbed is reemitted and passes through the material.
Opaque Materials
Reemitted light is reflected )passes back into the medium from which is came).
White Objects Reflect........
All Frequencies
Black Objects Reflect........
None
An Object as "Red
We see an object as red when it reflects red light.
Candlelight
Low in the higher frequencies (blue/violet) so it is yellowish.
Incandescent
Emits all visible frequencies but is richer in lower frequencies (red).
Fluorescent
Is richer in higher frequencies, (blue/violet).
Color of a Transparent Object
Color of a _____ object depends on the color of light it transmits.
Blue Glass 'Blue
Blue glass is blue because it absorbs all frequencies except blue. Blue light is transmitted through the glass.
Red Light Makes the Leaves Warmer
The petals reflect the red light and the green leaves absorb the red light causing the leaves to become warmer. (light energy is changed to heat energy in the leaves)
Green Light Black Rose Petals
The petals reflect only red light, they will absorb green light. If the green light is shining, there is no color to reflect and the petals will look black.
White Light From the Sun
White light is a composite (total) off all the visible frequencies.
Radiation curve" of Sunlight
Brightness of frequencies from the sun is uneven. Red and violet not as bright as the middle-range of frequencies (the yellow-green region).
Result of Visible Frequencies
White
Mixing Red, Green, and Blue Light
White
Red and Blue
Magenta
Red and Green
Yellow
Green and Blue
Cyan
Television Uses Additive Primary Colors
Red, blue, and green dots are lit in different combinations to produce all the different colors and white.
Magenta Complementary
Green
Cyan Complementary
Red
White - Specific Color
You get the complementary color.
White - Blue
Yellow
Paints and Dyes
They contain pigments that absorb light of certain range of frequencies and reflect light of other ranges of frequencies. (Pigments reflect a mixture of colors).
Primary Paint Colors
Red, Yellow, and Blue.
Mixing by Subtraction
Magenta, Yellow, Cyan. These are Subtractive primary colors.
Scattered Tiny Particles
________ particles in the air scatter high (blue/violet) frequencies of light.
Scattered Large Particles
________ particles in the air scatter low (red) frequencies of light.
Why the Sky is Blue
The tiny particles in the upper atmosphere (nitrogen and oxygen) scatter (reemit in all directs) the high frequencies (blue/violet). Our eyes are more sensitive to blue so we see the sky as blue.
Sky on the Moon Black
There are no molecules in the atmosphere of the moon to scatter the light so the sky is black.
Cloud White
Different sizes of water droplets cause all different frequencies to be scattered and all frequencies = white.
Sunsets Red
Sunlight reaches us through a longer path through the atmosphere at sunset. As light passes through this thicker atmosphere, light of the lower frequencies is transmitted (red) while light of the higher frequencies (blue/violet) is scattered.
Water is Greenish Blue
Water molecules absorb red and reflect cyan.
Glowing Red Neon Glass
The _____ light from glowing neon glass has a mixture of frequencies that are specific to neon. Neon has its own "fingerprint" of frequencies.
Atomic Spectra the "fingerprints" of Atoms
Light from each different element produces its own characteristics pattern of lines.
Color Blindness
Is a result of defective cones in the retina of the eye,
Cones
React to different frequencies, there is a cone for each color.
Rods
Opens the eye up from light to from dark, gray scale.
Colors of the Object
The color of the object depends on the light source. Or is due to they way the colors reflect light.
Color Mixing by Subtraction
Is the way pains and dyes get their color.
Color Mixing by Addition
Is the way light gets its color.
Smaller Particle Size
The higher the frequency scattered.
Violet Light
Is scattered more than blue but our eyes are not very sensitive to violet light.
Larger Particles
Scatter lower frequencies.
Sunrise and Sunset
Travels a longer path through the atmosphere.
True Ocean Color
Cyan
Water
Is transparent to almost all the frequencies of light.
Water Molecules
Resonate somewhat to the to the visible-red frequencies. This causes a gradual absorption of red light by water.
Electron
have well-defined energy levels--- lower energy near the atomic nucleus and higher energy farther from the nucleus.
Momentary
Excited state is only momentary, for the electron is quickly drawn back from its original or a lower level.
Electron Transit
The atom emits emits a pulse of light-- a photon.
Electrons release energy
in the form of light.
Continuous Spectrum
From an Incandescent bulb.
Line Spectra
comes from different elements.
Chemist
Use the line spectra to identify an element just a finger print is used to identify a person.
Atomic Composition
Of the sun and distant galaxies can be determined by examining the line spectra.
Longest Wave Color
Red
Highest Frequency of Color Visible
Violet
Violet Light
Although this frequency of light is scattered more than blue light, our eyes see the sky as blue because our eyes are more sensitive to blue light.
Oxygen and Nitrogen Molecules
Larger particles of these substances produce a whitish sky.
Red Light
Is scattered the least as it passes through the atmosphere.
Spectrum Emitted
The spectrum emitted by an element can be used to identify the element.
Candlelight
Emits light in the lower frequency range of colors.
Smaller Particle
The smaller the particle in the atmosphere, the higher the frequency of light it scatters.
Blue Sky
The sky appears blue because particles in the atmosphere scatter high-frequency light.
Sunset
Only lower-frequency light strike earth