ionising radiation Flashcards
what is ionising radiation?
-form of energy that acts by removing electrons from atoms and molecules
Alpha properties
-slow, heavy, high ionisation power
-travels 1-3cm in air
-stopped by a piece of paper or outer layers of skin
-harmful when ingested, damage cornea of eye,
Beta properties
-carry on positive or negative charge, small mass, so release with high energy
-travels 10s of centimetres
-stopped by clothing or layers of paper/plastic
-can cause burns if sufficient intensity, harmful if ingested as damages tissues/organs
Gamma properties
-smallest wavelength, most energy of any wave, weightless packets of energy called protons
-travels tens/hundreds of feet in air
-stopped by several feet of concrete/few inches of lead
-penetrate skin and damages DNA, most hazardous when inhaled or ingested
-cause cancer, cataracts
Definition of Half life
-time taken for the radioactivity of a specified isotope to fall to half its original value
Long half life isotope example
uranium-283
Short half life isotope example
technetium-99
Which pollutant property does half life determine?
persistence
definition of contamination
-something is carrying ionising radiation but not been absorbed by the body
definition of exposure
-when ionising radiation has been absorbed and absorbed entered the body
Who are most at risk from radiation exposure?
-cabin crew
-living in an areas with nuclear incident
-pilots
-people undergoing cancer treatment
Most common uses of radioactive materials and ionising radiation
-x-rays cancer treatment
-smoke alarms
-disinfection of medical instruments
-determining age of ancient artefacts using half lives for data
-creating/testing new medicines
-removing pathogens from food (sterilising)
-oil/gas exploration to test rock porosity
