1. example 7 Carbon-14 Dating Chapter 5.1 During the life of an organism, the ratio of carbon-14 (C-14) to carbon-12 (C-12) atoms remains about the same. When the organism dies, the ratio of C-14 atoms within its carcass begins to gradually decrease, but the C-12 does not, so they can be measured to see how many C-14 atoms were present at death. Comparing the number of C-14 atoms when it is discovered with the number at death can be used to find how long ago the organism lived. The ratio of the present amount of C-14 to the original amount t years ago is given by This gives a function that gives the amount remaining after t years. (Source: Thomas Jefferson National Accelerator Facility, http://www.jlab.org/) a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years?  2009 PBLPathways

2. During the life of an organism, the ratio of carbon-14 (C-14) to carbon-12 (C-12) atoms remains about the same. When the organism dies, the ratio of C-14 atoms within its carcass begins to gradually decrease, but the C-12 does not, so they can be measured to see how many C-14 atoms were present at death. Comparing the number of C-14 atoms when it is discovered with the number at death can be used to find how long ago the organism lived. The ratio of the present amount of C-14 to the original amount t years ago is given by This gives a function that gives the amount remaining after t years. (Source: Thomas Jefferson National Accelerator Facility, http://www.jlab.org/) a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years?

3.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

4.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

5.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

6.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

7.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

8.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

9.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining

10.  2009 PBLPathways a.If the original amount of carbon-14 present in an artifact is 100 grams, how much remains after 2000 years? b.What percent of the original amount of carbon-14 remains after 4500 years? Time in yearsOriginal amountAmount remaining