aliffeyip4erebell aliffeyip4erebell
  • 21-11-2016
  • Physics
contestada

the half life of a certain substance is 25 years. How long will it take for a sample of this substance to decay to 90% of its original amount ...?

Respuesta :

andriansp andriansp
  • 23-11-2016
10% =  1/2 ^n
*where n is number of half lives to reach 10%

n = ln10/ln2

and multiply by 25 gives 83.05 years to 2dp

Hope this helps
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