A piece of wood was burned and 7.32 g of CO2 was collected. The total radioactivity in CO2 was 7.6 dpm. How old was the wood sample ? Given t12 of C - 14 = 5730 years, specific activity of carbon obtained from a fresh wood sample is 15.2 dpm.
11460 years
Mass of carbon in 7.32 g CO2=1244×7.32=2g;
Activity per g(specific activity)=7.62=3.8 dpm
Fraction of activity remaining =3.815.2=14=(12)2
No. of half - lives clapsed = 2;
Age of the sample =2×5730 years