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Half-lifeof ""^(210)Pb is 22 years. 2gram of lead is allowed decay for 11 years. (a) How much lead is left?and (b) Whatis the percentage decay ? |
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Answer» Solution :Radioactive decay follows FIRST ORDER kinetics Number of half - lives `"(n)"=("Total - TIME")/("Half - life")=(11y)/(22y)=1/2=0.5`. (a) AMOUNT of lead left undecayed `=("Amount of lead taken")/(2^(n))=(2)/(sqrt(2))=1.414g` (b) Amount of lead decayed = Amount taken - left amount `=2-1.414=0.586g` Percentage pf lead decayed `=(0.586xx100)/(2)=29.3%`. |
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