Question

An archaeologist finds some ancient jewelry made from bone. The jewelry has a carbon mass of 303 g (HINT: Assume all the carbon is 12C and determine the number of atoms) and careful measurements show that the remaining 14C has a current decay rate of 14 decays/s. Determine the age of the bone (and presumably the jewelry). Remember, the ratio of 14C to 12C when the animal died was 1.3×10-12 & the half-life of 14C is 5730 y.

age of bone = ?

Answer 1

solution The number of carbon atom in femely in No : NA (3039) = (6.023 X1023) (303) = 1.520 x 1025 atomy The ratio of 14e te 12c won animal deed was - 2 Norue Noize = 1.381072 1.3810 Nome No - None Mone= 4.3 y 10-12 ( No - Norge ) Nopel &+ 1.341012) = (3.3 81012 ) No Nolue= (1-3 X 10 -12) V (1.5 20x 1025 ) 14.1.3 X10-12 Nolue = 1.97641013 Calculace the decay constant 0,692 1=0.693 - 5720 y/365day) (4.) ( 26 ) = 3.835 X 10125-1 .: +42 Ro=ANome Age of the bone by using R= Roelt

- 146 en f A No14 C R 0.693 I - 142 In :( 3.835 X 10^12)x(1.976 X 10'3) (57304) 0.693 tya feups 139624