Radioactivity Flashcards
what is annihilation?
it is when mass is converted to mass with two photons produced, which move 180 from each other.
Negatron is the most common beta
Positron exits shortly before interacting with a electron producing two gamma rays (0.51 MeV each)
what is internal conversion?
It is when electrons with discrete energies are emitted. Inner electron orbitals pass close to or through the nucleus, excess energy is given to the electron
Converted electrons leave with energy
It is when a bound electron becomes free
what does photon emission result in
The removal of an outer electron - AUGER electron, emitted when there’s excess energy given to the orbital energy
what is a curie?
radioactivity emitted from one gram of radium
how is stability achieved?
ejecting a charged particle from the nucleus
what is a nuclide?
nucleus described by its mass, atomic number and nucleon arrangement
what is an isomer?
same proton and neutron number but found in different energy states
what is radioactive disintegration?
change in nucleus structure resulting in a change in mass number or atomic number
what is disintegration
change from one nucleus (parent) to another (daughter)
what is radioactivity
number of disintegration’s per unit of time
what is half life
it is the time taken for half of the radioactive nuclei to decay into its daughter product
what type of nuclei is more likely to decay?
high atomic and large atoms as they are less stable, so require more neutrons
what is physical half life unaffected by?
physical or chemical conditions
what is biological half life?
it is when the radioactive source is found within the paganism, if it is excreted it is no longer a source of radiation exposure
what is the equation for half life
1/T effective = 1/T physical + 1/T biological
