Topic 3- radioactivity and ionising radia Flashcards
know the properties of
alpha, beta and gamma
positron radiation is
positively charged beta radiation
the positron is the antiparticle of
an electron
neutron radiation is
neutrons
unlike a b and g radiation, neutron radiation
doesn’t directly ionise, but can be absorbed by the nuclei of atoms in the substances they pass through
neutrons are absorbed best by
light nuclei
neutron absorption often leads to
gamma radiation emission
an isotope that lies above the curve had
too many neutrons
an isotope that lies below the curve has
too few neutrons
Beta- minus decay is the
emission of an electron from the nucleus
beta decay happens in isotopes that are neuron
rich
in beta decay,
the proton number increases by one, and the nucleon mass number stays the same
beta plus decay happens when
there are too few neutrons
in beta plus decay a proton gets changed into a neutron
a neutron
in beta plus decay
proton number decreases by one, nucleon number stays the same
alpha decay happens in very heavy atoms
proton number decreases by two, nucleon number decreases by four
gamma radiation is emitted from nuclei with
too much energy
gamma radiation is never
alone, always with a or b decay
up quarks have relative charge;……….. mass;
2/3 and 1/3
down quarks have relative charge;………… mass;
-1/3 and 1/3
neutron is made of
2 downs, one up
proton is made of
two up one down
neutron—> proton
makes beta decay emission
proton—> neutron
makes beta plus decay emission
isotope with short half life are used as
tracers in medicine
PET scanning can help
diagnose illnesses
radiation can cause
tissue damage and cell mutations
radiation can be used
internally or externally to treat tumours
using radiation in medical physics raises
social and ethical issues
developing medical techniques can be
controversial (animal testing)
