An archaeologist finds some ancient jewelry made from bone. the jewelry has a carbon mass of 127 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 21 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.

level 4 to level 2 : ))

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally