document.write( "Question 519070: The half-life of 234U, uranium-234, is 2.52 105 yr. If 98.2% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?
\n" ); document.write( " explain in deatil how to get this solved? \n" ); document.write( "
Algebra.Com's Answer #345388 by ankor@dixie-net.com(22740)\"\" \"About 
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\n" ); document.write( "The half-life of 234U, uranium-234, is 2.52(10^5) yrs.
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\n" ); document.write( " If 98.2% of the uranium in the original sample is present, what length of time (to the nearest thousand years) has elapsed?
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\n" ); document.write( "The half-life formula: A = Ao*2(-t/h)
\n" ); document.write( "where:
\n" ); document.write( "A = resulting amt after t yrs
\n" ); document.write( "Ao = initial amt
\n" ); document.write( "h = half-life of substance
\n" ); document.write( "t = time of decay
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\n" ); document.write( "Let initial amt; Ao = 100
\n" ); document.write( "A = 98.2, resulting amt
\n" ); document.write( "h = 2.52(10^5) yrs
\n" ); document.write( "find t
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\n" ); document.write( "100*2^(-t/(2.52(10^5)) = 98.2
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\n" ); document.write( "2^\"-t%2F2.52%2810%5E5%29\" = \"98.2%2F100\"
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\n" ); document.write( "2^\"-t%2F2.52%2810%5E5%29\" = .982
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\n" ); document.write( "\"-t%2F2.52%2810%5E5%29\"*ln(2) = ln(.982)
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\n" ); document.write( "\"-t%2F2.52%2810%5E5%29\" = \"ln%28.982%29%2Fln%282%29\"
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\n" ); document.write( "\"-t%2F2.52%2810%5E5%29\" = -.0262
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\n" ); document.write( "\"t+=+-.0262%2A-2.52%2810%5E5%29\"
\n" ); document.write( "t = 6,603.68 yrs\r
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