In the atmosphere, carbon dioxide is found in two forms, i.e., `^12CO_2` and `^14CO_2`. Plants absord `CO_2` during photosynthesis in presence of chlorophyll, plants systhesise glucose `6CO_2`+6`H_2O`rarr`C_6H_12O_6`+`6O_2uarr`
Half life of `^14CO_2` is 5760 years. The analysis of wooden artifacts for `^14C` and `^12C` gives useful information for determination of its age.
All living organisms, because of their constant exchange of Carbon dioxide with the surroundings have the same ratio of C-14 to C-12, i.e. `1.3xx10^-12`. When an organism dies, the C-14 in it keeps on decaying as follows:
`6^14Crarr7^14N+(-1)^0e`+Energy
Thus, the ratio of C-14 and C-12 decreases with the passage of time. We can measure the proportion of C-14 in the remains of dead organism and determine how long ago it died. The method of carbon dating can be used to date anything made or organic matter, e.g., bone, skeleton, wood, etc. Using carbon dating, materials have been dated to about 50,000 years with accuracy.
A piece of wood from an archeological source shows a C-14 activity which is 60% of the activity found in fresh wood today. The age of archeological sample will be:

Options

A. 4246 yrs
B. 4624 yrs
C. 4628 yrs
D. 6248 yrs

Answer

A