In simple words?

Question

can some one please explain carbon14 dating to me?

Answer 1

Carbon 14 has a very long half life. In carbon 14 dating then something dies, no more carbon 14 is formed in that object. In carbon 14 they measure how much carbon 14 there is in that example and compair it to that is found naturally. Then they do some maths to work out how old is is.

Answer 2

There are several isotopes of carbon. The stable form of carbon is primarily C12.

Comic rays are constantly bombarding the earth, hitting nitrogen14 atoms, and turning them into C14 atoms. The level of C14 in the environment is relatively constant.

So plants grow taking in carbon from the air. Animals grow taking carbon from the plants. At the time all this growing is occurring the ratio of C12 to C14 matches the ratio of C12 to C14 found in the environment.

As time passes more cosmic radiation hits the earth, and the C14 level is maintained at its constant level. And the ratio of C12 to C14 in the environment remains pretty much the same.

However, once that plant or animal stops growing – they stop taking in Carbon. Over time that C14 in the plant of animal decays back into N14. So as time goes on more C14 decays. Young stuff still has most of its C14, old stuff is missing most of its C14(its all turned back to nitrogen). Using the ratio of C12 to C14, we can predict the age of an item.

http://en.wikipedia.org/wiki/Carbon_dating

However carbon dating is not used as a stand alone tool, the stratigraphy of an archeological item is also very important. What events can be identified above and below the position of the item.