exponential decay y=Ce^k(t)

[cottoncndy88]

provided information:
half-life of isotope: 1620 yrs
amount after 1000 yrs: 1.5 grams

needed information:
initial quantity:
amount after 10,000 years:

I end up with the equation: 1.5=Ce^(1000)k
I cannot figure out how to solve for both variables with this equation and only this information. Thank you for your efforts.

 

[Gene]

First your equation is wrong. It is y=Ce^(kt)
You know that e^(k*1620) = .5 'cause 1620 is the half-life.
That lets you solve for k.
Then
1.5=Ce^(1000*k) lets you find C, the initial quantity.
Finally
y=Ce^(10,000*k)

 

[cottoncndy88]

Thank you very much!!!!!