document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=613732>Question 613732</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half-life of carbon-14 is 5700 years. Find the age of a sample at which 40% of the radioactive nuclei originally present have decayed </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #386247 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=386247\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The half-life of carbon-14 is 5700 years. Find the age of a sample at which 40% of the radioactive nuclei originally present have decayed<BR>\n" );
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document.write( "Carbon 14 Dating Formula:A=Ao2^-t/h, A=amt of radioactive material remaining after time t, Ao=amt initially present, h=half life of the material.<BR>\n" );
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document.write( "Amt of material present=60%<BR>\n" );
document.write( "60%Ao=Ao*2^-t/5700<BR>\n" );
document.write( "0.6=2^-t/5700<BR>\n" );
document.write( "take log of both sides<BR>\n" );
document.write( "log(.6)=-t/5700 log(2)<BR>\n" );
document.write( "-t/5700=log(.6)/log(2)<BR>\n" );
document.write( "-t=[log(.6)/log(2)]*5700&#8776;-4200<BR>\n" );
document.write( "sample is approximately 4200 years old </SPAN>\n" );
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