document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230272>Question 230272</A>: <I><SPAN STYLE=\"word-break: break-all;\"> uranium-235 is used as fuel for some nuclear reactors. it has a half life of 710 million years. how long will it take 10 grams of uranium-235 to decay to 1 gram?\r<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 #170671 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=170671\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> uranium-235 is used as fuel for some nuclear reactors.<BR>\n" );
document.write( " it has a half life of 710 million years. how long will it take 10 grams of uranium-235 to decay to 1 gram? <BR>\n" );
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document.write( "The half life equation<BR>\n" );
document.write( "Ao*2^(-t/h) = A<BR>\n" );
document.write( "where<BR>\n" );
document.write( "A is the resulting amt (1)<BR>\n" );
document.write( "Ao is the initial amt (10)<BR>\n" );
document.write( "t = time (in millions of yrs in this case)<BR>\n" );
document.write( "h = half-life of the substance (in millions of yrs) (710)<BR>\n" );
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document.write( "10*2^(-t/710) = 1<BR>\n" );
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document.write( "divide both sides by 10<BR>\n" );
document.write( "2^(-t/710) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F10 ALIGN=MIDDLE  ALT=\"1%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "2^(-t/710) = .1<BR>\n" );
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document.write( "use logs here<BR>\n" );
document.write( "log(2^(-t/710)) = log(.1)<BR>\n" );
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document.write( "log equiv of exponents<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F710 ALIGN=MIDDLE  ALT=\"-t%2F710\"   DISABLED_style= \"max-width:90%; height:auto;\" >*log(2) = log(.1)<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F710 ALIGN=MIDDLE  ALT=\"-t%2F710\"   DISABLED_style= \"max-width:90%; height:auto;\" >*.301 = -1<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-t%2F710 ALIGN=MIDDLE  ALT=\"-t%2F710\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-1%2F.301 ALIGN=MIDDLE  ALT=\"-1%2F.301\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "-t = 710*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-1%2F.301 ALIGN=MIDDLE  ALT=\"-1%2F.301\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = 2,358.569 million yrs<BR>\n" );
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document.write( "Check this on good calc: enter 10*2^(-2358.569/710) ~ 1.0<BR>\n" );
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