text: Because we are measuring the abundance of two isotopes of carbon, and because isotopes of the same element will be chemically identical, no ordinary process can preferentially remove C is going to be small enough to begin with, being only 0.0000000001% of atmospheric carbon, and then as the decay process progresses it's going to get smaller and smaller.After about 60,000 years the quantity will be too small for our instruments to measure accurately, and the best we'll be able to say is that the sample is about 60,000 years old or more.For this reason radiocarbon dating is of more interest to archaeologists than to geologists. Along with hydrogen, nitrogen, oxygen, phosphorus, and sulfur, carbon is a building block of biochemical molecules ranging from fats, proteins, and carbohydrates to active substances such as hormones.All carbon atoms have a nucleus containing six protons.