earth science
posted by lan .
if carbon 14 has a half life of 24 days how much would be left of 220 gram sample after 168 days

the amount left after t days is
220 (1/2)^(t/24)
so,
220(1/2)^(168/24) = 1.718g
168 days is 7 halflives, so 1/128 remains.