Topic 6 Flashcards
What is becquerel
The unit of radioactivity
Causes of background radiation
Living things contain radioactive materials
Some rocks are radioactive
Radon gas trapped in rocks or under house floors
The Sun and also Space
Main causes of background radiation in UK
- radon gas
- medical
- rocks
- some foods (bananas)
- nuclear power stations
- cosmic rays
What did Marie Curie discover?
Worked with ionising radiation
Made link between radioactivity and cancer
Ernest Rutherford
Discovered the atom
Henri Becquerel
Discovered radioactivity
Ionised gases
What does HLW, ILW and LLW mean?
High Level Waste (concrete -> metal container -> glass)
Intermediate Level Waste (metal container)
Low Level Waste (clothes/protection against radioactivity)
Problems with dumping barrels full of radioactive waste into the sea
Barrel is going to corrode
Radioactive substances will leak out
Contaminate food chain (fish will become radioactive)
Problems with firing radioactive substances into space
The shuttle containing it could explode
Problems with storage underground
You need to have a very stable geological site that never has earthquakes which is difficult to be sure of
What is a half life?
Time taken for a half ‘unstable’ nuclei to decay
What do you use to measure radioactivity
Geiger Müller tube
What does the term count rate mean for a Geiger Müller tube
Counts per second
What is the half life of the isotope Uranium?
700 million years
3 uses of radioactivity
Tracers in pipes (to find gas leaks)
Radiotherapy
Smoke detectors
How does a smoke alarm work?
The smoke absorbs the alpha (which is already in the alarm) which stops the current flowing and results in the alarm going off.
Difference between radiation and irradiation
Irradiation = when you expose something to radiation (which we do to some foods and medial equipment)
Radiation = when a nucleus decays and gives out alpa/beta/gamma radiation
Benefits of irradiating food
Lasts longer (as kills bacteria and microorganisms that decays it is sterilised by gamma rays)
Won’t get sick as safer to eat
Not radioactive
Drawbacks of irradiating food
Could destroy vitamins on food (get sick)
Still some germs left over
(Some say) it changes the taste of some food
Doesn’t destroy viruses
How can gamma rays be used to help diagnose and treat cancer?
Tracer = accumulates in area of cancer
Radiotherapy = fire a bit of radiation from lots of directions to kill cancer cells (without cutting brain open)
