Carbon dating can be used to estimate the age of any organic natural material, it has been used succesfully in archeology to determine the age of ancient artifact or fossil as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on earth. Since a radioactive substance such as carbon 14 has a known half life the amount of carbon 14 remaining in an object can be used to date that object. Carbon 14 hast a half life of 5,570 years which means that after that number of year half of the carbon 14 atoms have decayed into netrogen 14 it is the ratio of carbon 14 to nitrogen 14 in that substance that indicates the age of substen Ce. If for example in a particular sample the amount of carbon 14 is roughly equivalent to the amount of nitrogen 14 this indicates that roughly half of the carbon 14 has decayed into nitrogen 14 and the sample is approximately 5,570 year old. Carbon dating cannot be used affectively in dating objects that are older than 80. 000 years. When objects are old, much of the carbon 14 has already decayed into nitrogent 14 and the minuscule amount that
is left does not provide a reliable measurement of age. In the case of older objects other age dating methods are available, methods which use radioactive atoms with longer half lives carbon has. less