Intro to Astronomy
posted by M.T. .
The halflife of carbon 14, which is commonly used to date organic materials, is 5700 years. What is the minimum age of sample in which less than 1% of the organic carbon 14 is left?

If 1% is left,
(0.01) = (0.5)^N
where N is the number of halflives.
N = 6.644
minimum age = 37,900 years
There will be less than 1% left if the sample is older than that, so that is a minimum age.
There is not much about astronomy here 
Find the age for a rock for which you determine that 68% of the original uranium238 remains, while the other 32% has decayed into lead.
Respond to this Question
Similar Questions

Physics
Could someone help explain this problem to me . . . Carbon 14 has a halflife of 5700 year, scientist use this fact to determine the age of things made of organic material. Suppose the average page of a book containing aprox. 0.5mg … 
chemistry
A 1.00g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? 
chemistry
A 1.00g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? 
ChemB
The activity of carbon 14 in living tissue is 15.3 disintegrations per minute per gram of carbon. The limit for reliable determination of age is based on carbon 14 is .10 disintegration per min per gram of carbon. Calculate the max … 
algebra
carbon 14 has a hlf life of 5700 years. scientists use this fact to determine the age of things made up of organic material. Suppose the average page of a book containing approximitly .5 mg og carbon 14 was put into a time capsule. … 
Radioactivity
1. A granite rock is thought to be about 2 billion years old. why is it not possible to determine the age of the Rock using carbon14 dating? 
chemistry
The amount of organic carbon in a sample can be obtained by IR analysis of the carbon dioxide (CO2) released following complete combustion of the sample in oxygen. A reference sample of an organic compound is usually used to calibrate … 
Physics
(a)A fossilised tree was tested and contains 10 grams of Carbon14. Given that there was 12 grams of Carbon14 present when it died, determine the age of the fossil? 
Intermediate Maths
(a)A fossilised tree was tested and contains 10 grams of Carbon14. Given that there was 12 grams of Carbon14 present when it died, determine the age of the fossil? 
Final Maths
(a)A fossilised tree was tested and contains 10 grams of Carbon14. Given that there was 12 grams of Carbon14 present when it died, determine the age of the fossil?