What is carbon dating?

Answer 1

Carbon dating, or radiocarbon dating, uses the radiactive properties of carbon to determine how long an organism has been dead. Life on Earth is carbon-based, meaning that an Earthly organism is made largely from carbon compounds. Carbon on Earth exists in three isotopes. Carbon-12 has a natural abundance of 98.9%, and carbon-13's is 1.1%. There is also a trace of radiactive carbon-14, about 0.0000000001%. It has a half-life of 5730 years.

A living organism is constantly taking in carbon from the environment, and converting it into biological material. The absorption of carbon stops upon death. Since the natural abundance and decay rate of carbon-14 is known, scientists can measure the abundance of carbon-14 in a fossil to determine how much has decayed, thus how many half-lifes of carbon-14 have passed since the organism died, and thus how long ago it died.

Carbon dating can only be used for organisms that died up to about 60,000 years ago. Beyond that, there is so little carbon-14 left that it cannot be accurately measured.

Answer 2

This method of scientific dating is used for samples which were once alive (eg in bone, charcoal, leather). All of these contain carbon, a proportion of which is radioactive 14C, an isotope that is continuously being formed in the upper atmosphere. As living organisms take up radiocarbon along with other carbon atoms, the ratio between the two forms remains constant. However when they die the radiocarbon decays and is not replaced. Since it decays at a known constant rate, the decreasing concentration of 14C can be measured and the date when the material died estimated.

Answer 3

In nature, carbon atoms exist in two isotopic forms: carbon-12 and carbon-14. These two forms of carbon exist in nature in a particular ratio, and so all living organisms accumulate carbon of both forms in that ratio. When the organism dies, it is no longer adding new carbon atoms, but the C-14 atoms are radioactive and so decay at a very specific rate. By measuring the amount of C-14 remaining in a once-living thing, you can calculate when it died.

C-14 is good for determining the age of once living things that died less that 50,000 years ago, or so...

Answer 4

All living organisms take in carbon all during their lives. Carbon comes in c-12 and C-14, which is radioactive. The ratio in the environment is set. While an organism is alive it keeps taking in C , either by CO2 by photosynthesis, or by eating . After it dies, it no longer takes in C. The C-14 decomposes at a known rate. When an old bone or a piece of campfire wood is found, they check the ratio and it tells how long the piece has been dead.

Answer 5

A method of determining the age of an object. Cosmic rays interacting with nitrogen in the atmosphere create a certain amount of carbon-14, which is radioactive. The decay rate is known, so by measuring the amount of C-14 radioactivity in an artifact, its age can be determined. The rate of formation of C-14 has varied slightly over the last few millenia, so correction data has been obtained by comparing C-14 data with data obtained from dating wood by tree rings. Hence, C-14 age data is the most precise of the available radioactive dating methods. But the half-life of C-14 is short enough that it becomes of less use for dating things older than a few tens of thousands of years.

Answer 6

Taking a bit of coal to the cinema, followed by a KFC on the way home.


Oh and apparently it has something to do with the decay time of Carbon-14 - such that me measuring the decay, it is possible to ascertain the age of the thing you are dating. Quite clever

Loads more info and piccies too can be found here http://science.howstuffworks.com/carbon-141.htm

Answer 7

figuring out if somebody or something is older than old man mozz and how much older, using the properties of carbon -14.

Also about 2 people, i.e. 2 carbon based life forms, going out with the expressed interest of getting to know each other better.

Answer 8

It's a huge problem for radiometric dating, since C14 has been found in most coal seams which are assumed to be millions of years old, making them at most 100,000 years old. The usual explanation of contamination does not seem to hold water here.