atoms and radiation Flashcards
(14 cards)
who discovered radioactivity?
henri becquerel and marie curie
what does ionising mean?
it is able to add/ remove electrons -harmful
what is the activity of a radioactive isotope?
the rate at which it decays
what is activity measured in?
Bq
what are the characteristics of alpha particles? (4)
positively charged
strongly ionising
has a mass of 4
weakly penetrating
what are characteristics of gamma rays? (4)
weakly ionising
has a mass of 0
strongly penetrating
pure energy
what are characteristics of beta particles? ()
negative charge
weakly ionising
averagely penetrating
has a mass of 1-
what is nuclear fission?
the splitting of an atoms nucleus into two smaller nuclei
what is a half life?
the average time taken for half the radioactive nuclei to half
what does unstable uranium do when releasing neutrons and energy?
absorbs a neutron then splits into 2 smaller nuclei
what does nuclear fission result in?
a chain reaction
what happens if a chain reaction is uncontrolled?
heat builds up very quickly
what happens in nuclear fission?
small nuclei join together to form larger nuclei
what is contamination?
when radioactive particles escape into the environment
