P6 - Radioactivity

unstable nuclei

emits radiation and decays

ionising radiation

passes through matter and knocks electrons from atoms, leaving positive ions

why is ionising radiation dangerous

can damage DNA in living tissue and cause cancers

alpha radiation

high mass (4), high charge (2+), highly ionising with short range/low penetrating power

beta radiation

(comprimises electrons from nucleus) medium ionising, medium/medium penetrating power

gamma radiation

compromises a packet of high frequency electromagnetic radiation, low ionising, long range/high penetrating power

neutron decay

1 top, 0 bottom, n middle

whats stops each radiation

a: few sheets of paper, skin or cm of air/ b: few mm of aluminium/ g: few cm of lead of m of concrete

what is radiation detected with

geiger counter (becquerels)

half life

time it takes for the activity to fall by half

irradiation

when you exposed to radiation from a source outside the body

contamination

when radiation is inside or on a surface

where does background radiation come from

cosmic rays, radioactive radon gas leaking from ground

radiation in medicine

tracers, b or y used to treat cancer

nuclear fission

splitting nucleus in 2, dangerous as releases a lot of energy

nuclear fusion

combining 2 positive nuclei - creates huge amounts of energy

radiation from atoms

electrons can absorb radiation and move into a higher shell, producing an absorption line