$2$ points$)$ What particles are emitted in each step of the decay chain represented by

$238$

$92$U $234$

$90$Th $234$

$91$Pa $234$

$92$U $?$

$6.(3$ points$)$ A hospital needs to dispose of a waste containing $100$Ci$/$L of $131$I. How long must it be

stored until it decays to a radiation activity of $15$Ci$/$L$?$

P $2$ of $212$ points