Nuclear Radiation Flashcards
3 types of nuclear radiation
-alpha (α)
-beta(β)
-gamma(γ)
what is radioactive contamination
unwanted presence of substances containing radioactive atoms on or in other materials
what is radioactive decay
random emission from the nucleus of an atom
what is irradiation
exposing an object to nuclear radiation
what is the half-life of a radioactive source
-time taken for half of unstable nuclei to decay
or
-time taken for count rate to halve
what is count rate
number of decays each second (recorded by a geiger-muller tube)
what unit measures activity of a radioactive source
Becquerel (Bq)
what is radioactive activity
the rate at which a source of unstable nuclei decays
what are the equation symbols for alpha and beta particles
Alpha - helium (He 4 - mass 2-proton)
Beta - electron (e 0 - mass -1-proton)
which type of radiation doesn’t change the structure of the nucleus when emitted
gamma
which type of radiation doesn’t cause the mass to change but causes the charge of the nucleus to increase
beta
which type of radiation causes both the mass and charge of the nucleus to decrease
alpha
what materials can stop alpha, beta and gamma radiation
alpha=a sheet of paper/skin
beta=thin aluminium sheet
gamma=thick lead/concrete
what is the range in air of alpha, beta and gamma radiation
alpha=a few cm
beta=1m
gamma=infinite
which type of nuclear radiation is most ionising
alpha
