document.write( "Question 185467: b) HoHalf life of silicon 32 is 710 years. If a sample has 100 grams right now: a) How much will be present in 600 years? w much was present in 1809? \n" ); document.write( "
Algebra.Com's Answer #139152 by ankor@dixie-net.com(22740)\"\" \"About 
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Half life of silicon 32 is 710 years. If a sample has 100 grams right now:
\n" ); document.write( "a) How much will be present in 600 years?
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\n" ); document.write( "The half life equation: A = Ao*2^(-t/h)
\n" ); document.write( "Where
\n" ); document.write( "A = Resulting amt after t years
\n" ); document.write( "Ao = initial amt (t=0)
\n" ); document.write( "t = time in years
\n" ); document.write( "h = half life of substance in years
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\n" ); document.write( "A = 100* 2^(-600/710)
\n" ); document.write( "Find 2^(-60/71) on a calc
\n" ); document.write( "A = 100 * .55668
\n" ); document.write( "A = 55.67 grms after 600 yrs
\n" ); document.write( ":
\n" ); document.write( "b) How much was present in 1809:
\n" ); document.write( "that would be 2009 - 1809 = 200 years ago; we want to Find Ao 200 yrs ago
\n" ); document.write( ":
\n" ); document.write( "100 = Ao* 2^(-200/710)
\n" ); document.write( "Find 2^(-20/71) on a calc
\n" ); document.write( "100 = .8226*Ao
\n" ); document.write( "Ao = 100/.8226
\n" ); document.write( "Ao = 121.56 grms were present 200 yrs ago \n" ); document.write( "
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