radiocarbon dating

[bucket]

I don't understand how this works :S.

[cara.mel]

Carbon-14 is an unstable isotope of carbon.
Different living things have different amounts of the stuff in them when they are alive.
If you can estimate how much it had when it was alive (this is the most inaccurate part of the whole calculation), and count how much is left today, you can work out how old it is by how much that has decayed from the original amount.

However I haven't done biol at all so if you need it for VCE at all then listen to someone else

[bucket]

uhm, is the product that it is broken down into still present in the fossil/thing-thats-being-radiocarbon-dated when they make this calculation?

[Faraz]

Yes it will be present, what happens is that the atom losses its radioactivity so in carbon dating when it is at 3/4 it means that the carbon has lost a 3rd of its radioactivity...

[bturville]

They know the half life for the unstable form of carbon (5730 yrs).

From knowing what the atmospheric ratios were (thats how they calibrate the whole process) they can calculate the age. So say that there was 1% C-14 in a sample orginally and now its 0.5%, the sample "should" be about 5730 years old.

[bucket]

hahaha cheers for the answer