Question Number 52457 by Necxx last updated on 07/Jan/19
$${Two}\:{radioactive}\:{elements}\:{A}\:{and}\:{B} \\ $$$${has}\:{half}\:{lives}\:{of}\:\mathrm{100}\:{and}\:\mathrm{50}{years}. \\ $$$${Samples}\:{of}\:{A}\:{and}\:{B}\:{initial}\:{contains} \\ $$$${equal}\:{numbers}\:{of}\:{atoms}.{What}\:{is} \\ $$$${the}\:{ratio}\:{of}\:{the}\:{remaining}\:{atoms} \\ $$$${of}\:{A}\:{to}\:{that}\:{of}\:{B}\:{after}\:\mathrm{200}{years}? \\ $$
Answered by MJS last updated on 07/Jan/19
$${t}=\mathrm{000}\:{A}=\mathrm{100\%}\:{B}=\mathrm{100\%}\:{A}:{B}=\mathrm{1}:\mathrm{1} \\ $$$${t}=\mathrm{100}\:{A}=\mathrm{50\%}\:\:{B}=\mathrm{25\%}\:{A}:{B}=\mathrm{2}:\mathrm{1} \\ $$$${t}=\mathrm{200}\:{A}=\mathrm{25\%}\:{B}=\mathrm{6}.\mathrm{25\%}\:{A}:{B}=\mathrm{4}:\mathrm{1} \\ $$