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Old Dec 8th 2014, 03:44 AM   #1
TechExpressInc
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half life ?

How old is a vase if the amount of sodium24 found in the vase 1/32 of what should be there if the half-life of sodium24 is 10.2 years?
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Old Dec 10th 2014, 02:45 PM   #2
bjhopper
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half life

equation for exponential decay
A=A0 e^-rt
A=0.5 A0 =1
Solve equation for r
using this r solve the following equation
1/32*0.5 = 0.5 e ^-rt
take the ln (nat log ) of both sides
my answer vase is61.1 years old
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Old Dec 23rd 2014, 06:02 AM   #3
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