document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1199030>Question 1199030</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The half life of a certain isotope is 8.5 hours. If we have a sample of 20 ounces of that isotope, how much of it will remain after one full day?\r<BR>\n" );
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document.write( "The correct answer is one of the following.  Which one is correct?\r<BR>\n" );
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document.write( "A) 0.28 ounces \r<BR>\n" );
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document.write( "B) 0.14 ounces \r<BR>\n" );
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document.write( "C) 1.41 ounces \r<BR>\n" );
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document.write( "D) 2.82 ounces  </SPAN>\n" );
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document.write( "Half-life Formula<BR>\n" );
document.write( "y = a*(0.5)^(x/H)\r<BR>\n" );
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document.write( "We have:<BR>\n" );
document.write( "a = 20 = starting amount in ounces<BR>\n" );
document.write( "H = 8.5 = half-life in hours<BR>\n" );
document.write( "x = 24 = number of hours<BR>\n" );
document.write( "y = number of ounces left after x hours\r<BR>\n" );
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document.write( "So,<BR>\n" );
document.write( "y = a*(0.5)^(x/H)<BR>\n" );
document.write( "y = 20*(0.5)^(24/8.5)<BR>\n" );
document.write( "y = 2.82528945857332<BR>\n" );
document.write( "y = 2.83<BR>\n" );
document.write( "After a full 24 hours, there should be about 2.83 ounces of material remaining.\r<BR>\n" );
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document.write( "It appears there might be some rounding error either on my part, or perhaps your teacher made a typo somewhere. \r<BR>\n" );
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document.write( "The closest value to this is <font color=red>D) 2.82 ounces</font> which is likely the final answer.<BR>\n" );
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document.write( " </SPAN>\n" );
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