Determining Absolute Age 12/7/16 Determining Absolute Age objective: I will model rates of radioactive decay through a graphing activity. PAGE 45

Absolute Age absolute age- the exact numeric age of an object or event

Radiometric Dating method of using radioactive decay to measure absolute age

Radiometric Dating rocks contain unstable radioactive isotopes that emit particles (decay)

Half-Life time required for half of a sample of radioactive isotopes to break down (decay) half-life is always constant for a particular isotope

Half-Life parent isotope- original radioactive isotope daughter isotope- newly formed stable isotope

Half-Life scientists compare the ratio of the parent and daughter isotopes to calculate absolute age higher % of daughter isotope = more half-lives higher % of parent isotope = less half-lives

Radioactive Isotopes Uranium-238 (238U): very long half-life (4.5 billion years) useful for dating geologic samples more than 10 million years old Carbon-14 (14C): short half-life (5730 years) used to date once living samples less than 70,000 years old

Output Activity (Page 44) Illustrate Figure 4 from page 194 of the Holt Textbook Create a key to represent the parent and daughter isotopes Label each part of the diagram with: the % of parent isotope that has decayed into the daughter isotope the % of the parent isotope that has not decayed

Output Activity (Page 44) Using the diagram from page 194, answer the following question. Write both the question and answer. 1) Scientists discover a fossil and use radiometric carbon dating to find its age. The fossil contains a 3 to 1 ratio of the daughter isotope, Nitrogen-14, compared to its parent isotope, Carbon-14. How old is the fossil? (the half-life of Carbon-14 is 5,730 years)

Extra Credit Answer questions #28,29,30 from page 203 in your textbook. Each correct answer earns 3 points on tomorrow’s Quiz. Write your answers on a separate piece of paper and submit them when you are finished. You must show your work!