document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1129845>Question 1129845</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half-life of element X is 13.25 minutes, if the orginal of the sample is 2.36 kg, how long will it take in HOURS for the remaining mass to be 12.0 grams ?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #746476 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=746476\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The half-life of element X is 13.25 minutes,<BR>\n" );
document.write( " if the original of the sample is 2.36 kg,<BR>\n" );
document.write( " how long will it take in HOURS for the remaining mass to be 12.0 grams ?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "The radio active decay formula<BR>\n" );
document.write( "A = Ao*2^(-t/h) where<BR>\n" );
document.write( "A = remaining amt after t time<BR>\n" );
document.write( "Ao = initial amt<BR>\n" );
document.write( "t = time of decay<BR>\n" );
document.write( "h = half-life of substance <BR>\n" );
document.write( ":<BR>\n" );
document.write( "Change 2.36 kg to 2360 grams<BR>\n" );
document.write( "2360*2^(-t/13.25} = 12<BR>\n" );
document.write( "2^(-t/13.25) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12%2F2360 ALIGN=MIDDLE  ALT=\"12%2F2360\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%282%5E%28-t%2F13.25%29%29 ALIGN=MIDDLE  ALT=\"ln%282%5E%28-t%2F13.25%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%2812%2F2360%29 ALIGN=MIDDLE  ALT=\"ln%2812%2F2360%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "the log equiv of exponents<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F13.25 ALIGN=MIDDLE  ALT=\"-t%2F13.25\"   DISABLED_style= \"max-width:90%; height:auto;\" >ln(2) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%2812%2F2360%29 ALIGN=MIDDLE  ALT=\"ln%2812%2F2360%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F13.25 ALIGN=MIDDLE  ALT=\"-t%2F13.25\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%2812%2F2360%29%2Fln%282%29 ALIGN=MIDDLE  ALT=\"ln%2812%2F2360%29%2Fln%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Using our calc<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F13.25 ALIGN=MIDDLE  ALT=\"-t%2F13.25\"   DISABLED_style= \"max-width:90%; height:auto;\" > = -7.61961<BR>\n" );
document.write( "t = -13.25 * -7.61961<BR>\n" );
document.write( "t = 100.9598 ~ 101 minutes<BR>\n" );
document.write( "which is<BR>\n" );
document.write( "101/60 = 1.68 hrs<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );