SOLUTION: This is a word problem relating to exponential functions: The half-life of a substance is 250 years. If there were initially 100 grams of the substance, what is the exponential

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Question 1168430: This is a word problem relating to exponential functions:
The half-life of a substance is 250 years. If there were initially 100 grams of the substance, what is the exponential model for the situation? And how much will remain after 500 years?
Thank you so much in advance. Have a good day!

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The half-life of a substance is 250 years.
If there were initially 100 grams of the substance, what is the exponential model for the situation?
:
The half-life decay model
A = Ao*2^(-t/h) where
A = remaining amt after t time
Ao = initial amt
t = time of decay
h = half-life of substance
:
In this problem
A = 100*2^(-t/250)
:
And how much will remain after 500 years?
A = 100*2^(-500/250)
A = 100*2^(-2)
reciprocal gets rid of the negative on the exponent
A = 100*1%2F2%5E2%29
A = 100*1%2F4
A = 25 grams remain after 500 years