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December 22, 2014

December 22, 2014

Posted by **Sandhya** on Friday, April 18, 2008 at 9:16pm.

2) What is the activity of a sample of 14C that contains 1.22E+21 nuclei?

- physics-Radioactivity -
**Damon**, Saturday, April 19, 2008 at 4:53pm1) n(t) = No e^-kt

where n is number at t and No is starting number

when t = 15. n/No = 1/17 = .0588

so

.0588 = e^-15k

ln .0588 = -15 k

k = -2.833/-15 = .18888

so

what is t when n/No = 1/2 ??

.5 = e^-.18888 t

ln .5 = -.693 = -.18888 t

t = 3.67 days half life

- physics-Radioactivity -
**Sandhya**, Saturday, April 19, 2008 at 10:58pmThanks a lot Damon

Is my answer for the second problem correct?

- physics-Radioactivity -

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