I kinda got stuck on this one here.

It says:

Einsteinium (254Es) has a half-life of 270 days. How much of a 5-gram sample would remain after 2160 days?

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- Oct 24th 2008, 09:21 PMdc52789Just needed help on this one
I kinda got stuck on this one here.

It says:

Einsteinium (254Es) has a half-life of 270 days. How much of a 5-gram sample would remain after 2160 days? - Oct 24th 2008, 09:44 PMJhevon
recall that $\displaystyle r = \frac {\ln 2}{\text{half life}}$

use that $\displaystyle r$ in the exponential decay formula: $\displaystyle N(t) = N_0e^{-rt}$

where $\displaystyle N(t)$ is the amount remaining after time $\displaystyle t$, $\displaystyle N_0$ is the initial amount, $\displaystyle r$ is the rate of decay

you want to find $\displaystyle N(2160)$ - Oct 24th 2008, 09:59 PMdc52789
- Oct 24th 2008, 10:06 PMJhevon
- Oct 24th 2008, 10:11 PMdc52789
- Oct 24th 2008, 10:16 PMJhevon
- Oct 24th 2008, 10:19 PMdc52789
- Oct 24th 2008, 10:44 PMJhevon
- Oct 25th 2008, 05:12 AMHallsofIvy
- Oct 25th 2008, 08:00 AMdc52789