In the atmosphere, carbon dioxide is found in two forms, i.e., .^(12)CO_(2) and .^(14)CO_(2). Plants absorb CO_(2) during photosynthesis. In presence of chlorophyll, plants synthesise glucose. 6 CO_(2) + 6 H_(2) O to overset(hv)(to) C_(6)H_(12)O_(6) + 6O_(2) uarr Half life of .^(14)C is 5760 years. The analysis of wooden artifacts for .^(14)C and .^(12)C gives useful information for deermination of its age. all living organisms, because of their constant exchange of CO_(2) with the surrounding have the same ratio of .^(14)C to .^(12)C, i.e., 1.3 xx 10^(-12). When an organism dies, the .^(14)C in it keeps on decaying as follows: ._(6)^(14)C to ._(7)^(14)N + ._(-1)^(0)e + Energy Thus, the ratio .^(14)C//^(12)C decrease with the passage of time. we can be used to date anything made of organic matter, e.g., bone, skeleton, wood, etc. Using carbon dating material have been dated to about 50,000 years with accuracy. In the process of photosythesis, O_(2) gas is released form: