radioactivity Flashcards
(26 cards)
what is an alpha particle and what are its properties?
2 protons 2 neutrons (helium nucleus)
least penetrating
most ionising
what is a beta particle and what are it’s properties
it is an electron (fast moving)
in between gamma ray and alpha particle
what is a gamma ray and what are it’s properties
electromagnetic wave
most penetrating
least ionising
what stops an alpha particle
paper
OR
30cm air
what stops a beta particle
few mm of aluminium
what stops gamma ray
few cm lead
what is activity and what unit
number of decays per second
in Becquerels
what are some causes of background radiation (only need to know a few)
buildings
food and drink
cosmic rays
rocks
hospitals
radon gas
in an experiment how far do you put the Geiger Muller tube away from the radioactive source
20cm
in an experiment what do you attach the geiger muller tube to
a counter
what is alpha radiation used in and why
smoke detectors
easily absorbed
what is beta radiation(electron) used for and why
it is an electron
to check thickness of metal
what is gamma radiation (electromagnetic wave) used for and why
sterilising medical equipment
radiotherapy
gamma rays are most penetrating so can kill cancer cells
what is contamination
having radiation inside you
what is irradiation
exposure to radiation from the outside
what is the half life
time taken for half of the parent nuclei to decay
what is fission
where does it happen
WHAT DOES IT RELEASE
large nucleus splits into 2 smaller nuclei
RELEASING ENERGY
nuclear power plants (reactors)
what is fusion
where does it happen
WHAT DOES IT RELEASE
when 2 small nuclei join together
RELEASING ENERGY
the sun and stars
how does fission occur
high speed neutron shot at uranium 235
becomes unstable (236)
breaks up
forming 2 daughter nuclei
shoots neutrons out also
causing chain reaction
fuel rod
contains uranium
control rod
controls rate of reaction by absorbing the neutrons
moderator
slows down neutrons
shielding
absorbs radiation + protects people
what is ionising definition
ability of radiation to create an ion
