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Flashcards in Uses of radiation Deck (10):
1

Smoke detectors use [ ] radiation, how? (3 steps)

Alpha
1.A weak source of alpha radiation is placed in the detector close to 2 electrodes
2.The source causes ionisation, and a current flows between he electrodes
3.If there is a fire then the smoke will absorb the radiation, so the current stops and the alarm sounds

2

Tracers in medicine always have [ ] half life beta or [ ] emitters

short
gamma

3

How are radioactive isotopes used as tracers?

They're injected/ swallowed by patients and their progress around the body is monitored using an external detecor

4

Give an example of an isotope that is used to test the thyroid gland

Iodine-131
Tests whether the gland is taking in iodine as it should

5

Radiotherapy uses [ ]

Gamma rays

6

What 2 things have to be checked when using gamma radiation to kill cancer cells?, why?

Right dosage and directed carefully. High doses of Gamma rays will kill all living cells, you don't want to kill normal cells.

7

Food can be exposed to [ ] doses of [ ] which will kill all microbes, keepeing the food [ ] for longer

high
gamma rays
fresher

8

Medical instruments can be [ ] by gamma rays

sterilised

9

State an advantage of irradiation over boiling

Doesn't involve high temps so things like apples and plastic can be sterilised without damage
food isn't radioactive afterwards

10

The isotope used for irradiation (sterilisation) needs to be a very strong [ ] emitter of gamma rays with a reasonably [ ] half-life (at least several [ ]) so that it doesn't need replacing too often.

strong
long
months