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Name the regions of the electromagnetic spectrum
- Microwave through far infrared
- Near infrared
- Gamma rays
- High energy gamma rays
Describe radio waves and their main interaction with matter.
Collective oscillation of charge carriers in bulk material (plasma oscillation). An example would be the oscillation of the electrons in an antenna.
What are the main matter interactions with microwave to far infrared radiation?
Plasma oscillation, molecular rotation
What are the main matter interactions with near infrared radiation?
Molecular vibration, plasma oscillation (in metals only)
What are the main matter interactions with visible radiation?
Molecular electron excitation (including pigment molecules found in the human retina), plasma oscillations (in metals only)
What are the main matter interactions of ultraviolet radiation?
Excitation of molecular and atomic valence electrons, including ejection of the electrons (photoelectric effect)
What are the main matter interactions with radiation of X-rays?
Excitation and ejection of core atomic electrons, Compton scattering (for low atomic numbers)
What are the main interaction of matter with gamma rays?
Energetic ejection of core electrons in heavy elements, Compton scattering (for all atomic numbers), excitation of atomic nuclei, including dissociation of nuclei
What are the main interactions with matter of high energy gamma rays?
Creation of particle-antiparticle pairs. At very high energies a single photon can create a shower of high energy particles and antiparticles upon interaction with matter.
What is the relationship to energy as the wavelengths increase?
It is inversely proportional. As wavelengths size increases, the amount of energy within them decreases.
What is the wavelength range for gamma rays and their relative size to a real object?
- Gamma ray: <10e-12 m
- Size: sub-atomic level
What is the wavelength range of X-rays and their relative size to a real object?
- X-ray: 10 nm - 0.01 nm
- Size is molecules to atoms
What is the wavelength range of ultraviolet (UV) waves and their relative size to a real object?
- UV light: 400 nm - 1 nm
- Size is bacteria to molecules
What is the wavelength range of the visible spectrum and relative size to a real object?
- Visible: 750 nm - 400 nm
- Size of protozoans and bacteria
What is the wavelength range of infrared radiation and is realtive size to real objects?
- Near infrared: 2500 nm - 750 nm (2.5 um - 750 nm)
- Infrared: 250,000 nm - 2,500 nm (25um - 2.5 um)
- Size of grains of sugar to protozoans
What is the wavelength range of microwaves and its size to a real object?
- Microwaves: 250,000 - 1,000,000,000 nm (25 um - 1 mm)
- Size of adult humans to grains of sugar
What is the wavelength range for radio waves and relative size to a real object?
- Radio: >1 mm (1000 m to 1 m)
- Size of buildings to adult humans.
What are plasma oscillations?
Plasma oscillations, also known as "Langmuir waves" (after Irving Langmuir), are rapid oscillations of the electron density in conducting media such as plasmas or metals. The frequency only depends weakly on the wavelength.
What is plasma?
Plasma is the fourth state of matter. It is an ionized gas, where the gas that has been energized to the point that some of the electrons break free from, but travel with, their nucleus - in other words allows both species of ions and electrons to coexist.
As far as we know, plasmas are the most common state of matter in the universe. Essentially, the sun, like most stars, is a great big ball of plasma. The sun's enormous heat rips electrons off the hydrogen and helium molecules that make up the sun.
They are even common here on earth. A spark in a gas will create a plasma. A hot gas passing through a big spark will turn the gas stream into a plasma that can be useful. Plasma torches like that are used in industry to cut metals.
What is the wavelength range of ultraviolet (UV) light?
ulatraviolet = 10 - 400 nm
What is the wavelength range of violet range?
Violet = 455 - 390 nm
What is the wavelength range of blue light?
Blue = 492 - 455 nm
What is the wavelength range of cyan light?
Cyan = 520 - 500 nm
What is the wavelength range of green light?
Green = 577 - 492 nm
What is the wavelength range of yellow light?
Yellow = 597 - 577 nm
What is the wavelength range of orange light?
Orange = 622 - 597 nm
What is the wavelength range of red light?
Red = 780 - 622 nm
What is the wavelength range of infrared radiation?
Infrared = 750 nm - 1 mm
What are the waves of the Electromagnetic Spectrum of Radiation?
All of these waves are electric and magnetic forces - forces which vary with time in direction and intensity.
What is the speed of all the waves of the Electromagnetic Spectrum of Radiation?
All have speed 186,000 miles per second = c = speed of light !
186,000 miles/sec (299,792 km/sec)
How do the waves of the Electromagnetic Spectrum of Radiation move through space?
They move through vacuum,and do not need a 'carrier'. Speed decreases after entering materials
In layman's terms, describe the Electromagnetic Spectrum of Radiation (EMS).
On one end of the spectrum are radio waves with wavelengths billions of times longer than those of visible light. A small portion in the middle is the visible light - a rainbow of colors that we can see. On the other end of the spectrum are gamma rays. These have wavelengths millions of times smaller than those of visible light.