document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=363788>Question 363788</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If a 50g sample of substance Z decays to 47g in 11 days, what is the half-life of substance Z? Give your answer to the nearest day. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #259441 by </B><A HREF=/tutors/aboutme.mpl?userid=amoresroy><B>amoresroy(361)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=amoresroy><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=amoresroy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=259441\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> half-life = elapsed time * log 2 / log (beginning amount/ending amount)<BR>\n" );
document.write( "              <BR>\n" );
document.write( "elapsed time = 11/365 = 0.030136986<BR>\n" );
document.write( "beginning amount = 50g<BR>\n" );
document.write( "ending amount = 47g\r<BR>\n" );
document.write( "\n" );
document.write( "Use a scientific calculator to solve this.\r<BR>\n" );
document.write( "\n" );
document.write( "half-life = 0.030136986 * log2 / log (50g/47g)<BR>\n" );
document.write( "          = 0.337603726<BR>\n" );
document.write( "          = 365*0.337603726<BR>\n" );
document.write( "          = 123.23 days   <BR>\n" );
document.write( "          = 123 days               \r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );