Final answer:
The breakdown of carbon-14 to nitrogen-14 is measured using the concept of half-life, which is 5,730 years for carbon-14. This is utilized in carbon dating to determine the age of fossils.
Step-by-step explanation:
The unit of measurement that describes the breakdown of carbon-14 (C-14) to nitrogen-14 (N-14) when determining the age of a fossil is called the half-life. The half-life of C-14 is about 5,730 years, and it is used in a method known as carbon dating or radiocarbon dating. This process utilizes the decay of C-14 to N-14 in a former living organism to calculate its age, as the organism stops absorbing C-14 once it dies. Measuring the remaining amount of C-14 in comparison to the expected level in a living organism allows scientists to estimate the time since death of the specimen. If an organism has half the starting concentration of C-14, it is estimated to have died approximately 5,730 years ago.