radioactivity
- Created by: rxbyw
- Created on: 18-01-19 20:48
radioactivity:
radioactive decay=unstable isotopes giving out radiation to become more stable
unaffected by temp and chemical bonding
radioactive substances emit ionising radiation which is radiation that removes electrons from atoms
alpha radiation:
2 neutrons+protons-same to a helium nucleus
+2 charge
4 mass
big heavy
short penetration distance
high ionisation
absorbed by sheet of paper
beta radiation:
an electron
-1 charge
0 mass
small
medium penetration distance
medium ionisation
absorbed by a sheet of aluminium
gama radiation:
short wavelength electromagnetic wave
no mass or charge
high penetration distance
weakly ionsing
absorbed by sheets of lead
activity+half life:
radiation is measured with a Geiger-Muller tube which records count rate
radioactive decay is random-you cant predict which or when a nucleus will decay
half life=the time it takes for the number of nuclei of a radioactive isotope in a sample to halve
older sources emit less radiation
activity is measured in becquerels(Bq)
short half life means activity falls quickly
dangerous because they emit high amount…
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