document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1163965>Question 1163965</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the decay rate of Arsenic-74 when the half- life is 17.5 days.  Round to six decimal places. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #788219 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=788219\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "A radioactive substance decays at a rate proportional to the amount remaining.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ A(t)\ =\ A_oe^{\lambda t}\">\r<BR>\n" );
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document.write( "When half-life is reached, <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{A(t)}{A_o}\ =\ \frac{1}{2}\">\r<BR>\n" );
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document.write( "Hence the name \"half-life\"\r<BR>\n" );
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document.write( "Since the half-life of this particular substance is 17.5 days:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ e^{17.5\lambda}\ =\ \frac{1}{2}\">\r<BR>\n" );
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document.write( "Take the natural log of both sides\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ 17.5\lambda\ =\ \ln\(\frac{1}{2}\)\ =\ \ln(1)\ -\ \ln(2)\ =\ -\ln(2)\">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \lambda\ =\ \frac{-\ln(2)}{17.5}\">\r<BR>\n" );
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document.write( "You can do any additional arithmetic required.\r<BR>\n" );
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document.write( "I sincerely hope you are not surprised that the answer is a negative number.\r<BR>\n" );
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document.write( "																<BR>\n" );
document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \ \\r\"> </SPAN>\n" );
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