atomic physics - background radiation and radiation safety Flashcards
natural and artificial sources, health effects, handling radioactive samples, geiger-muller
who discovered radioactivity and how
henri becquerel
he placed uranium salts on top of a photographic plate inside an envelope
when he returned the photographic plate had developed and it could have only been from the uranium
he worked with pierre and marie curie to discover several radioactive elements
what is background radiation
most carbon in the universe is a very stable carbon-12 however every one in 10 milli carbon atoms is an unstable, radioactive carbon-14
some have isotopes that decay over time, releasing radioactive particles or waves to the surroundings - background radiation
natural sources of background radiation
10% - cosmic rays
12% - food & drink
14% - ground and building
51% - radon in atmosphere
artificial sources of background radiation
0.1% - nuclear power discharges
0.2% - non-medical industry use
0.2% - tv sets
0.4% - fallout from weapon tests
12% - medical usage
how is radiation measured
in millisieverts (mSv)
what is the biggest danger in encountering radiation
ionisation - to give an atom/molecule a charge which will then react with something else leading to mutations
ways to work safely with small quantities of radioactive substances (5)
- only authorised personnel to handle radioactive substances; signed in and out when required
- users may wear a special badge which shows how much radiation they’ve been exposed to (gets foggy if exposed to too much)
- gloves must be worn and tongs used
- never direct sources towards others or yourselves
- put away sources in a lead-lined box once finished
explain the use of a geiger-muller counter
the tube of it is pointed towards the source and the counter measures how many radioactive particles are detected
always take the background radiation measurement beforehand and subtract from any reading taken - we don’t want naturally-occurring radioactive particles interfering with experiments
