document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140477>Question 1140477</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half-life of gold-195m is approximately 30.5 seconds.\r<BR>\n" );
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document.write( "Step 1 of 3 :  Determine a so that A(t)=A0at describes the amount of gold-195m left after t seconds, where A0 is the amount at time t=0. Round to six decimal places.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #761035 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=761035\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> N=Noe^(-kt)<BR>\n" );
document.write( "half-life is where N=1/2 No so N/No=1/2<BR>\n" );
document.write( "ln (1/2)=-kt, since ln e^-kt is -kt<BR>\n" );
document.write( "-0.693=-kt, but don't round yet.<BR>\n" );
document.write( "t=30.5 in this instance<BR>\n" );
document.write( "so 0.693=30.5 k<BR>\n" );
document.write( "k=0.022726<BR>\n" );
document.write( "A(t)=Aoe^-0.022726t<BR>\n" );
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