The Earth's atmosphere contains various isotopes of carbon, roughly in constant proportions. These include the main stable isotope (12
C) and an unstable isotope (14
C). Through photosynthesis, plants absorb both forms from carbon dioxide in the atmosphere. When an organism dies, it contains the standard ratio of 14
C to 12
C, but as the 14
C decays with no possibility of replenishment, the proportion of carbon 14 decreases at a known constant rate.
The time taken for it to reduce by half is…
Words 5706 - Pages 23
