document.write( "Question 729751: A particular radioactive isotope decays from 220 milligrams (mg) to 184.8 mg in 17 days. Find the half life of the isotope.
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Algebra.Com's Answer #446235 by josgarithmetic(39617) $\"\"$ $\"About$

You can put this solution on YOUR website!
General form, $\"A%28t%29=I%2Ae%5E%28-k%2At%29\"$ , I means initial amount, A(t) is amount at time t.\r
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\n" ); document.write( "\n" ); document.write( " $\"184.8=220%2Ae%5E%28-k%2A17%29\"$
\n" ); document.write( " $\"%28184.8%2F220%29=e%5E%28-k%2A17%29\"$
\n" ); document.write( " $\"0.84=e%5E%28-k%2A17%29\"$
\n" ); document.write( " $\"ln%280.84%29=-k%2A17%2Aln%28e%29\"$
\n" ); document.write( " $\"-%281%2F17%29%2Aln%280.84%29=k\"$
\n" ); document.write( " $\"highlight%28k=0.01026%29\"$ \r
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\n" ); document.write( "\n" ); document.write( "The specific model equation is $\"highlight%28A%28t%29=I%2Ae%5E%28-0.01026%2At%29%29\"$ . Half Life is found through $\"1%2F2=1%2Ae%5E%28-0.01026%2At%29\"$ , and you want to find t. \n" ); document.write( "

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