Chapter 3 Concepts Flashcards
Who developed the electromagnetic theory?
James Maxwell
Characteristics of electromagnetic radiation (3)
has no mass,carries energy in waves as electric and magnetic disturbances in space, travels at the speed of light.
Name lowest energy to highest energy on the electromagnetic spectrum
Radio Waves, Microwaves, Infrared Light, Visible Light, Ultraviolet Light, X-Rays, Gamma Rays.
Wave lengths are measured in____
meters (m)
Frequencies are measured in ____
hertz (Hz)
Electromagnetic energy can exist apart from matter and travel through____
a vacuum
There is a ______ relationship between frequency and energy
Direct. As frequency increases, energy increases.
How does electromagnetic energy differ from mechanical energy?
It does not require a medium which to travel through. The energy itself vibrates.
Electromagnetic energy can only exist as ____
photons
The relationship between Wave length and Frequency is ________
Inverse. As the wave length decreases, the frequency increases.
The speed of light in exponential form
3x10^8 m/s
Electromagnetic radiation exhibits properties of ______ and ________
waves, and particles.
_______act more like particles and ______ are more like waves
high energy, low energy
The inverse square law is used to calculate what?
the change in the intensity (quantity) of radiation reaching the image receptor with changes is distance.
What is the formula for the inverse square law?
i1 (d2)^2
—- = ———
i2 (d1)^2
Where do Gamma Rays originate?
in the nuclei of atoms and they represent the excess energy the atom is giving off to reach a stable state.
Where do X-Rays originate?
Through interactions between electrons and atoms.
How are X-rays produced?
when fast moving electrons within the x-ray tube strike atoms of the metal in its target.
What electromagnetic radiation is commonly used in MRI?
Radio waves.
What is the unit for radioactive decay?
Curie/ Becquerel
Where do beta particles originate?
an unstable nucleus
What is a positron
It is a beta particle (aka electron) with a positive charge.
What is an ion pair?
The atom and the electron that was removed from it during ionization.
Subatomic make up of an alpha particle
2 protons and 2 neutrons
