1. Tuesday, September 23, 2014 Wednesday, September 24, 2014 Tuesday, September 23, 2014 Wednesday, September 24, 2014 Absolute Age / Radioactive Dating Determining Absolute Age Essential Questions (leave space to answer): 1. How do rocks provide evidence of earth’s absolute age? • Absolute Age –assigns a quantitative estimate of the number of years ago an event occurred. • Determining Absolute Age… • Radioactive Dating – using radioactive particles found in a rock to determine the actual age of the rock • Radioactivity – Radioactivity is a process in which subatomic particles escape from the nuclei of unstable atoms releasing energy. • See diagram atom Warm Up What is radioactive dating? How is that different from relative dating? • Homework: • Bring in plain M&M’s or Skittles for a “sweet” lab! • Choose an element from the half- life chart and create a graph representing the daughter and parent element over time. • Test – October 1 and 2 Page 19 Page 20

2. Which rocks do geologist use? -Igneous rocks are most useful due to unique chemical makeup. Radioactive materials are unchanged. • Sedimentary rock is not as reliable because it’s made of many different rock particles • Metamorphic dating usually results in the age of the change, not the original rock

4. Determining Absolute Age Use an element’s Half-life: The time it takes for an element to decay. Examples: Carbon-14 has a half-life of 5,730 years. Always found in LIVING organisms Potassium-40 has a half-life of 1.3 billion years Half Life You Tube Using a specific calculation can help you determine the absolute age using half-lives

5. Visuals Help with Radioactive DecaySee page 57A in textbook. Original Rock 3 Half Lives 4 Half Lives 1 Half Life 2 Half Lives

6. Practice Time!!!Copy this chart Element Y is found in an igneous rock and we are trying to determine the rocks age. We know Y’s half life is approximately 3,000 years and that the rock is currently 6.25% radioactive. How old is the rock? Element X is found in an igneous rock and we are trying to determine the rocks age. We know X’s half life is approximately 3,000 years and that the rock is currently 50% radioactive. How old is the rock? Element Z is found in an igneous rock and we are trying to determine the rocks age. We know Z’s half life is approximately 3,000 years and that the rock is currently 25% radioactive. How old is the rock? 100% Radioactive Igneous Rock 94% decayed 50% decayed 87.5% decayed 50% Radio- active 75% decayed 25% r-a 12.5% 6% Three Half Lives Four Half Lives One Half Life Two Half Lives

7. Graph Examples

8. Graph Example

10. LAST PRACTICE ITEM FOR TODAY!!! Closure - Venn Diagram Relative and Absolute Age

11. Thursday, September 25, 2014 Friday, September 26, 2014 Friday, September 19, 2014 Monday, September 22, 2014 M&M Lab and Article Review M&M Lab and Article Review Essential Questions (leave space to answer): How can two sided objects be used as a model for radioactive decay? • Now it’s time for a sweet model !! • Two person TEAMS • 1 – chief investigator and reader • A = organized, sometimes organized, disorganized • B = Clear, almost clear, confusing • Timekeeper and Communicator • A = organized, sometimes organized, disorganized • B = Clear, almost clear, confusing • Materials (per pair) • 2 cups • 25 candies (M&Ms or Skittles) • paper towel • Summary questions in your notebook. • After the lab pick up an article to read. Warm Up: Pennies have two sides. Each time you flip a coin, what is the probability of getting heads or tails? ______ If given 10 coins, how could you demonstrate the half-life of elements? Propose an experiment using 2 sided coins. (________) • Homework: • Make sure all Essential Questions between pages 13 and 21 are answered thoroughly. • Relative and Absolute Age Test next Wed / Thurs • Notebook check next class Page 21 Page 22

12. SchoolNet Quizhttps://cms.powerschool.com/public__CY8WA7JE7_ • 10 Question open notebook quiz • Read questions carefully • Use a calculator if needed • Select an answer for all questions • After the quiz, go to Ms. Jenner’s wiki to access the enrichment activity.

13. Wrapping up A - How did today’s activity model radioactive decay of material? B - Explain the similarities between the graph created today and the graph you created for homework. C - Argue that radioactive dating is more effective at determining the actual age of a rock than the Law of Superposition.

14. Check Out How did today’s activity model radioactive decay of material? Communicate to your partner one thing they did well and one area for improvement from the rubric.

15. Monday, September 29, 2014 Tuesday, September 30, 2014 Monday, September 29, 2014 Tuesday, September 30, 2014 ? M&M Lab and Article Review Essential Questions (leave space to answer): Warm Up: Homework: Page 23 Page 24

16. 3-2-1 Article SummaryResponses must be based on the article. • 3 elements used for radioactive dating • 2 objects commonly dated using radioactive dating • 1 thing that helped you learn this concept the best