rate = initial rate e^-kt
1/2 = e^-k(5600)
ln .5 = -5600 k
-.693147 = - 5600 k
so
k = 1.2378 *10^-4
now
1 = 16 e^-1.2378 *10^-4 t
ln 1/16 = -1.2378 *10^-4 t
t = 22,400
or do it in your head
1/16 = (1/2)^4
so 4 * 5600 = 22400 :) LOL
A gram of living plant material with Carbon-14 , decays at a rate of about 16 disintegrations per minute. When the plant dies, the Carbon-14 decays, with a half-life of 5600 years. A gram of the dead plant is found to decay at about 1 disintegration per minute. Calculate the probable age of the plant.
1 answer