Can carbon dating
Plants get their share of carbon atoms from the atmosphere. It is seen that at any given point of time, the ratio of stable carbon and radiocarbon in the atmosphere, is almost same as the ratio of stable carbon and radiocarbon in living organisms like plants, animals, and humans.
When a living organism dies, its carbon intake ceases.
For example, logs of woods cut from different trees were burnt in a fireplace.
The sample of the end result would be contaminated.
The ratio of carbon-12 and carbon-14 is determined by three techniques, namely gas proportional counting, liquid scintillation counting, and accelerator mass spectrometry.✶ Let's say that the given sample has 15 percent carbon-14, as compared to the living sample. Then the age of the given sample would be:t = [ ln (.15) / (-.693) ] x 5700 years = [ ln (-1.897) / (-.693) ] x 5700 years = 1.3146 x 5700 years = 7493 years old► Carbon dating cannot be used to date organisms that doesn't intake carbon dioxide form the air.
Consider a shell or bone deposited during the Ice Age.
Would it have started out with more or less C-14 than today’s shells or bones?
From that point onwards, the unstable carbon-14 decays with its half life of almost 5700 years, and the amount of carbon-12 remains the same.
Hence, gradually, the ratio of stable carbon to radioactive carbon also decreases.