Radio waves, X rays, gamma rays, and visible light are all part of the
electromagnetic spectrum
what type of electromagnetic wave can cause sunburn?
ultraviolet radiation
True or False, Electromagnetic waves can be produced by oscillations of electrons.
true
what type of electromagnetic wave do we feel as heat?
infared radiation
what is the part of the electromagnetic spectrum do we see with our eyes?
visible light
what is the name of the type of wave with high frequency and a wavelength of 10 to .001 nanometers?
X-rays
what is the name of the ray that is the highest frequency wave in the electromagnetic spectrum and is generated in nuclear reactions?
gamma rays
Compare red light and blue light in terms of the energy, wavelength, and frequency of both types of light
Red light has a longer wavelength than blue light, red light has lower energy than blue light, and red light has a lower frequency than blue light
The speed of light changes as it passes through different materials due to the absorption and emission of the light by atoms. As the speed changes, does its frequency, wavelength, or both change?
The wavelength changes but the frequency does not change
How is the index of refraction for a material dependent upon the speed of light?
The index of refraction for a material is the ratio of the speed of light in a vacuum to the speed of light in that material.
Is it possible for a material to have an index of refraction less than 1?
no
List two different ways that microwaves are used.
to cook food and they are used by radars
When a beam of X rays is passed through a person's body and onto a special film, a radiograph (or X-ray photograph) is created. How do radiographs enable a doctor to "see" a broken arm?
Film is sensitive to exposure to X rays (or other light forms). Calcium and other elements in your bones absorb X rays more than the soft tissue in your body. The absorption by bone prevents the X rays from striking the film resulting in unexposed areas o
The following are different types of electromagnetic waves. Gamma rays, visible light, X rays, microwaves, radio waves, infrared light, ultraviolet light. Arrange these waves in order from LOWEST energy to HIGHEST energy
radiowaves, microwaves, infared waves, visible light, ultraviolet light, X rays and gamma rays
For the electromagnetic waves (Gamma rays, visible light, X rays, microwaves, radio waves, infrared light, ultraviolet light), does it make sense to order them by their speed? yes or no? and why or why not?
no, all rays go the speed of light which is the same, 3.0x10 to the 8th
Calculate the wavelength of violet light that has a frequency of 7.40 1014 Hz.
.000000405 meters
What is the frequency of a microwave with a 16 centimeter wavelength?
1875000000 HZ
The speed of light in a vacuum is 3.0 108 m/sec. What is the speed of light in flint glass whose index of refraction is 1.56?
192307692 m/sec
If light travels at 1.5x10 to the 8th m/sec through zircon, what is the index of refraction of zircon?
2.01
what does light pass through that makes it go only 1 orientation?
a polarizer
what measures the wavelength of light?
a spectrometer
what is the orientation of light vibrations?
polarization
what creates interference patterns when light passes through it?
diffraction grating
light is a wave for four reasons, list those reasons
Light shows the same relationship between speed, frequency, and wavelength as other waves/ Light can be reflected, refracted, diffracted, and absorbed, Light waves have frequency, wavelength, and speed/ Light waves can resonate and exhibit interference
How is an interference pattern of light created? In your answer, use the terms constructive interference and destructive interference.
An interference pattern is a pattern of alternating bright and dark patterns of light created by passing light waves through a diffraction grating. The bright bands are where the light waves meet with constructive interference and the dark bands are where
Thomas Young demonstrated that light is a wave. What experiment did he use and what evidence did his experiment create?
His double slit experiment created an interference pattern
What is a spectrometer used for?
It is a device used to identify the components of light and measures their wavelengths
What causes the central spot when light goes through a diffraction grating?
The light passing straight through the diffraction grating causes the central spot
What causes the first order bright spots?
Constructive interference between waves that are one wavelength out of phase causes the first order bright spots
Is an electromagnetic wave a transverse or longitudinal wave?
transverse
What does it mean to say a light wave is polarized?
A light wave is polarized when it has a single orientation
Explain what a polarizer does to unpolarized light
It allows light of a particular orientation to pass through and absorbs the rest
A polarizer transmits 37% of a light's intensity, and the transmitted light is oriented horizontally. How much of the light intensity was absorbed, and what is the orientation of this light?
63% of the light is absorbed, and it is oriented vertically
A red laser with a wavelength of 650 nanometers is passed through a diffraction grating. What would you expect to see?
You would expect to see a bright central spot, then on either side you would see the first order bright spots, second order bright spots, and so on. Because only one kind of light is used (red light), the spots will be very well-defined.
what is the process of releasing stored energy as light?
photoluminescence
what are particles of light energy known as?
photons
How is the intensity of light related to photons?
The number and energy of photons determines the intensity of light
How is a photon's color related to its energy?
Each photon has its own color. Each color relates to a specific energy. The lowest energy photons we can see are red; the highest energy are blue
What "charges up" glow-in-the-dark plastic?
When glow-in-the-dark plastic is exposed to light, phosphorus atoms absorb the energy from the photons. Then the atoms slowly release the stored energy and the plastic glows. The plastic is "charged up" by absorbing energy from light.
Does it matter what color light you use to charge up the glow in the dark plastic?
yes, light with higher energy will affect it much more than light with a lower energy
In the subtractive color process, pigments absorb some colors and reflect some colors of light. Explain the absorption and reflection of colors of an object in terms of atoms and electrons
When light interacts with an atom, energy is absorbed with the result being an electron moving to a higher energy level. At the higher energy level, the electron is unstable. Therefore, eventually, the electron moves back to a lower level and emits its en
Photographers use a special scale called Color Temperature for comparing the colors of light sources when they take pictures. Color temperature is the temperature in Kelvins at which that color light would be emitted. Which would have the higher color tem
a blue flashbulb
At 600�C, a heating element produces red light. Is red light also present when a light bulb filament makes white light at 2000�C?
yes white light has all the colors in it, not just one
A blacksmith can tell the temperature of a metal piece by looking by its color. You know that the order of colors in a rainbow is ROYGBIV. Which color would a blacksmith see first, red or white, as he heats up the metal to the highest temperature of 2600�
He sees red first