document.write( "Question 1148203: I need some help with this problem?
\n" ); document.write( "The half-life of radium is 1690 years. If 30 grams are present now, how much will be present in 210 years? \n" ); document.write( "

Algebra.Com's Answer #769576 by ikleyn(52782) $\"\"$ $\"About$

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document.write( "The general formula for the remaining amount is\r\n" );
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document.write( "    M(t) = M(0)*2^(-t/1690),\r\n" );
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document.write( "where  M(0)  is the initial mass in grams;  t is the time in years.\r\n" );
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document.write( "Substitute your data to get\r\n" );
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document.write( "    M(in 210 years) = 30*2^(-210/1690) = 30*2^(-0.12426) = 27.524 grams (approximately)    ANSWER\r\n" );
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