# How is carbon 14 used to date fossils?

##### 2 Answers

Carbon 14 has half life of 5 700 years which is useful in dating fossils. The ratio of the carbon 14 and its stable daughter (Nitrogen 14) defines its age.

#### Explanation:

Carbon 14 has half life of 5 700 years which is useful in dating fossils.

In other words, if a 100 gram of a fossil contains 50 grams of carbon 14 and 50 grams of nitrogen 14, we can say that the object is about 5 700 years old.

100 grams= 25 grams carbon 14 and 75 grams nitrogen 14. We can say that it is about 11 400 years.We can use logarithms to solve the problem.

Carbon 14 is not used to date fossils.

#### Explanation:

With a half-life of only 5,700 years Carbon 14 can only be used to date items of that are relatively recent and still contain carbon residue.

At 57,000 years which is ten half lives the original amount of radioactive carbon 14 will be

this is 1/ 1024 or about .0001 or .01 percent effectively there is no Carbon 14 left to measure.

Also must objects that are considered to be fossils have been petrified turned to stone, there is no carbon left to measure.

Carbon 14 is useless in dating fossils unless it is believed that Dinosaur bones are less that 50,000 years old. Radioactive half lives are not used to date fossils.