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April 21, 2014

April 21, 2014

Posted by **Krys** on Tuesday, January 25, 2011 at 11:16pm.

- Science Half Lives -
**DrBob222**, Tuesday, January 25, 2011 at 11:21pmThis way.

k = 0.693/t_{1/2}

You don't have any units for the half life of 2.7 WHAT? Make sure unit for this agrees with unit below (in days).

Substitute k into the equation below.

ln(No/N) = kt

No = what you start with--400 g

solve for N, the number left after time t.

k from above.

t = time = 10.8 days.

- Science Half Lives -
**Krys**, Wednesday, January 26, 2011 at 12:48am2.7 days.. so the answer is 25 g ?

- Science Half Lives -
**kiri**, Wednesday, October 17, 2012 at 12:05pm1. billion

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