The half-life of gold-194 is approximately 1.6 days. How much of a 9 gram sample of gold-194 would remain after 2 days?

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Answer 1 · 2018-04-14T09:57:39

#"3.79 g"#

Rate constant of reaction is

#k = ln(2)/t_"1/2"#

#k = ln(2)/"1.6 days" = "0.433 days"^-1#

Fro radioactive decay, sample left after time #t# is given by

#"N"_t = "N"_0 e^(-kt)#

#"N"_"t" = "9 g" × e^(-"0.433 days"^-1 × "2 days")#

#"N"_"t" = "9 g" × e^-0.866#

#"N"_"t" = "3.79 g"#