Chemistry

Problem

A solution contains a mixture of isotopes of

X^{A1}

(

t_{1/2} = 14 \text{ days}

) and

X^{A2}

(

t_{1/2} = 25 \text{ days}

). Total activity is 1 curie at

t = 0

. The activity reduces by 50% in 20 days. Find: a. the initial activities of

X^{A1}

and

X^{A2}

. b. the ratio of their initial no. of nuclei.