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Ch 4 Bushong
EM Energy
Question | Answer |
---|---|
An xray photon is | a quantum of EM energy. It has both electric and magnetic properties |
A quantum is | a small bundle of energy traveling thru space at the speed of light |
The velocity of EM radiation is | 3x10(8)m/s or 186000 miles per sec |
Amplitude | 1 half the range from crest to valley over which the sine wave varies |
Freq and wavelength | wavelength and freq are inversely propotional |
Frequency and unit | (f) the number of wavelengths passing a point of observation per second. Hz |
Wavelength unit and formula | Represnted by lambda. W=v/f or c/f |
EM wave eqaution | F=c(v)/lambda...same for velocity and wavelength |
Photon energy and frequency | Photon energy and frequency is directly proportional |
What 3 things on the EM spectrum have the ability to penetrate matter | Cosmic, Gamma, Xray |
Visible light and prism | when it passes through a prism, white light is refracted into its component colors. These colors have wavelengths from 400-700 |
Smallest segment of the EM spectrum | visible light |
Way to remember EM spectrum in order from highest frequest and lowest wavelength to vv | Colons get xrayed under very intense radiation |
UV light | located between visible light and ionizing radiation. Its molecular interaction can cause sunburn |
Infrared light | Located b/t visible and microwave. Heats any substance it shines on. Is considered radiant heat |
Radiowaves, wavelength and energy | Radio waves cover a large portion of the EM spectrum. They have long wave lengths and low energy. All radiowaves are identical in frequency |
Types of radiowaves | Am radio wavelengths are about 100m. Very short RF wavelengths and microwave radiation |
Ionizing radiation 3 | IR is known by the energy contained in a photon. an xray photon contains more energy than RF or visible photons. The freq is higher and the wavelengths are much shorter |
The only difference between xray and gamma | their origin. xrays are produced outside the nucleus, gamma rays are produced inside the nucleus of radioactive atoms |
Wave particle duality | Visible light acts more like a wave, xray as a particle. Photons interact with matter most easily when the matter is the same size as the photons wavelength |
Radiation attenuation | The reduction in intensity resulting from scattering and absorption |
Light attenuation | Light is reflected, absorbed, or attenuated depending on the composition of the surface on which its incident |
Another word for not absorbing light at all | Transmission or transparent |
Another word for partially absorbing light | Attenuated or translucent |
Another word for completely absorbing light | absorption or opaque |
Attenuation of xrays and the 2 terms | Structures that attenuate xrays are described as radiolucent (soft tissue) or radiopaque (bone) depending on the relative degree of xray transmission or absorption |
Particle Model:Quantum Theory | The xray photon is a discrete bundle of energy. The energy of a photon is directly porpotional to its frequency |
Planck's Quantum Equation | E=hf. E energy, h plancks constant. can all be switched or. E=hc/lambda |
EM Radiation visualized as | all EM radiation can be visualized as 2 perpendicular sine waves traveling in a straight line at the speed of light. 1 sine waves is an electric field, the other magnetic field |
Law of conservation of energy | states that energy cannot be created nor destroyed |
According to quantum physics: (and 1 ex) | Matter can be transformed into energy and vice versa. Pair production is an ex of tranforming energy into mass |
Einsteins theory of relativity | E=mc2. E is energy in J. m is mass in kg. and c is velocity of light in m/s |
Mass and Energy | They are 2 forms of the same medium |
Plancks number constant | 6.63 x 10-34 m2kg/s |