
Decay rates
I'm having second thoughts on the answers I came up with...
Einsteinium235 decays at a rate of 3.406% per day.
a. find the annual decay rate in exact form:
100(.96594)^365
b. Compute an approximation of your solution in part a accurate to two decimal places:
(This is where I was thrown off, as my equation truncated to two decimal places comes out to be 0.00, and I'm sure that's not the intention.)
3.21 x 10^4
c. Find the halflife of Einsteinium235 in exact form:
100(.96594)^t=50
log(96.594^t)=log(50)
t x log(96.594)=log(50)
t=(log(50))/(log(96.594))
d. Compute an approximation of your solution in part c accurate to two decimal places
0.85
(But I know that's obviously wrong. (Headbang))
Any help appreciated.

Halflife can easily be gotten from the formula
$\displaystyle k=\frac{1}{T}ln(2)$
$\displaystyle k=ln(.96594)$
You know k, enter it in and solve for T.

What about my decay rate?
