- the smallest quantity of any type of energy
- it contains no charge or mass
- in waveform or sine wave
another name of photon is
bundle of energy
- Draw a sine wave and label crest, valley, amplitude and wavelength
Valley is also called trough
What is common among all the electromagnetic
All travel at the speed of light
What is the velocity of all electromagnetic radiation
distance from one crest to another
Amplitude of a wave
one half of the range from crest to valley
Frequency of a wave
Number of wavelengths that pass a point of
observation per second
Shorter the wavelength, higher the frequency
Explain the relationship between wavelength and frequency.
They are inversely propotional
electromagnetic wave equation
What is the relationship between the energy of a photon and its frequency?
Energy of a photon is directly proportional to its frequency
- Higher the frequency, higher the energy
- Higher the frequency higher the penetration.
- Shorter the wavelength, higher the frequency
- Shorter the wavelength, higher the penetration.
is diagnostic ultrasound a part of the electromagnetic spectrum?
- Ultrasound is a wave of moving molecules
- Doesn’t have constant velocity
Although photons of visible light travel in straight lines, their course can be deviated when they passed from one transparent medium to another this deviation in line of travel
Wave Particle Duality
- Visible-light photons tend to behave more like waves than particles
- even though it is electromagnetic it can behave like particles in waves sometimes
- Ex. x-ray
What is the difference between radiopaque and radiolucent?
Structures that absorb x-rays
Structures that transmit x-rays
Like soft tissue
Objects absorb light in three degrees
- Not at all (transmission)
- Partially (attenuation)
- Completely (absorption)
Inverse square law
The inverse square law describes the relationship between radiation intensity and distance from the radiation source.
Can be applied to distances greater than 7 times the longest dimension of the source
Planck’s quantum theory
The energy of a photon is directly proportional to its frequency
E = hf
(E = MCC)
E equal MC2
the change of energy in radiation as it passes through body
linear acceleration make it possible to produce xray or gamma rays to treat cancer cells