Molecular iodine, I$2($g$),$ dissociates into iodine atoms at $625$ K with a first$-$order rate constant of $0\mathrm{.}271$ s$-1.$

$($a$)$ What is the half$-$life for this reaction?

s

$($b$)$ If you start with $0\mathrm{.}054$ M I$2$ at this temperature, how much will remain after $5\mathrm{.}29$ s assuming that the iodine atoms do not recombine to form I$2?$

M