Dating biology

Scientists often use the value of 10 half-lives to indicate when a radioactive isotope will be gone, or rather, when a very negligible amount is still left.

dating biology-83dating biology-57

The half-life is the time required for half of the original sample of radioactive nuclei to decay.

For example, if you start off with 1000 radioactive nuclei with a half-life of 10 days, you would have 500 left after 10 days; you would have 250 left after 20 days (2 half-lives); and so on.

Once the organism dies, the amount of carbon-14 reduces by the fixed half-life - or the time required for half of the original sample of radioactive nuclei to decay - of 5,730 years, and can be measured by scientists for up to 10 half-lives.

Measuring the amount of radioactive carbon-14 remaining makes it possible to work out how old the artifact is, whether it's a fossilized skeleton or a magnificent piece of artwork.

Libby was awarded the Nobel Prize in chemistry for his work in 1960.

Carbon dioxide in the atmosphere contains a constant amount of carbon-14, and as long as an organism is living, the amount of carbon-14 inside it is the same as the atmosphere.It is often used on valuable artwork to confirm authenticity.For example, look at this image of the opening of King Tutankhamen's tomb near Luxor, Egypt during the 1920s.You might remember that it was mentioned earlier that the amount of carbon-14 in living things is the same as the atmosphere.Once they die, they stop taking in carbon-14, and the amount present starts to decrease at a constant half-life rate.Carbon dating was used routinely from the 1950s onward, and it confirmed the age of these historical remains.

Tags: , ,