what is the significance of calculating the half life of a reaction?

How has the concept of half-life been used to develop the method of carbon dating?
If a substance does not contain the element carbon can the method of carbon dating be used to date the artifact?


Thanks!

1 answer

http://en.wikipedia.org/wiki/Half-life

See the above for q 1 and 2.
For q 3, depending upon the age, the method may be used. Here is another link that describes the other "dating" methods starting with paragraph 3 then see the table just below that with a list of the other radiometric possibilities if the material doesn't contain C.