radiation Flashcards
what is an isotope
same number of protons and element dif number of neutrons
when does radiation happen
some isotopes have an unstable neucleas so they give out radiation to stabalise
what is count rate
amount of decays per sec recorded on a counter
what are decays measured in
bequerels (bq)
explain findings of gold leaf
eanest rutherford fired alpha particles at a metal foil and to his shock found a very small amount were completely deflected. he realised there had to be a very small and dense neucleas in the middle
why was the plum pudding model discharged
couldnt explain how some alpha particles were deflected at large angles
what did bohr do
explained the shells that electrons orbit and how they can absorb or emit electro magneticradiation to change orbits
properties of alpha particles
same as a helium ion
mass number 4 atomic 2
not very peentrating only goes like 5cm and stopped by paper
very ionising
what does ionising mean
knocking electrons off a substance by radiation, does not make it radioactive per se
properties of beta particles
medium sized
pretty ionising
can go fairly far
consists of fast moving electrons
stopped by a sheet of aliminium
atomic number of -1, it comes from a neutron split into a pro and an elec leaving the neucleas with one less neutron and one more proton
gamma raddiation properties
notvery ionising
can move very far
only stopped by a thick sheet of lead
how to reduce ionising exposure
keep as far away as possible
spend little time in high risk areas
stay behind barriers
what is activity
Total amount of decaf
what is radioactive decay like
completely random
uses of radiation
smoke alarms send out alpha particles intoa gap in the alarm which is then aborbed by smoke 9in the event of a fire, triggering the alarm
