uses of nuclear radiation

what is a medical tracer

radioactive isotope that can be used to track the movement of substances e.g. blood around the body

how do medical tracers work

PET scan detects the gamma rays emitted from the tracer to diagnose cancer + determine location of tumour

how do smoke detectors work

• when there’s no smoke = circuit is complete

• smoke blocks current = an alarm sounds

• the alpha radiation ionises the air to create a current across the circuit gap

how does the nuclear radiation measure the thickness of materials

• thicker material = more particles absorbed so count rate falls

• thinner material = less particles absorbed so count rate increases

why do we sterilise food and medical equipment with nuclear radiation

• gamma rays is used due to high penetration to irradiate all sides of medical equipmenrt iwthout removing packaging

• food = irradiated to make it last longer and reduce risk of food-borne infections

how does carbon dating work

• all living things take in stable carbon-12 and radioactive carbon-14 (radioactive)

• organism dies = stop's taking in carbon-14

• the carbon-14 starts to decay by beta decay

why wouldn’t carbon dating work on a wooden boat

you don’t know when the wood was cut

why would carbon-dating not be accurate after 50 000 years

there’s too little of it to be sure of the age

what can affect carbon dating

contamination or changes in atmospheric carbon levels

how is carbon-14 formed

cosmic rays converting nitrogen-14 to carbon-14

what is carbon dating

the measurement of age of an organic material through the amount of carbon-14 in the material

which nuclear radiation is used in radiotherapy treatement

gamma rays

how does radiotherapy work

directed at cancerous tumour as they can penetrate body

what nuclear radiation is used to measure the thickness of materials

beta rays

what nuclear radiation is used to sterilise food and medical equipment

gamma rays