radioactivity

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  • 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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