5200 Well, I hope you all had a wonderful spring break! It's time to get back to studying algebra now. Today you will be demonstrating your knowledge of negative exponents using internet sites provided and the Claris work spreadsheet. Half lives are the amount of time it takes for half of a substance to decay or disappear. The disappearance of C14 or carbon 14 is used to determine how old a once living thing is. We can determine how old a fossil is by counting the number of half lives or the amount of time it takes for half of the C14 in an object to disappear. ( Sort of like the disappearing cookie activity we did yesterday.) You will be reading about a historical shroud, the shroud of turin, making a spreadsheet in Claris Works, and then graphing the information from your spread sheet. In your spreadsheet you will need to compare your starting amount of C14 to your new amount of C14 after a given amount of half lives provided. In addition you will need to make a comparison to the number of grams left after so many half lives have gone by to the number of years it will take to decay that much C14. Instructions: . Click on second to last web link and read about how half lives are determined. . Click on last site and read about the difficulties using carbon dating to date this shroud and why it is important. Then click on last link in this location " The Shroud of Turin and the 1988 Controversy" . Design a spread sheet as below demonstrating the relationships mentionioed above. .When finished completing data for your spread sheet, highlight the "# after half life" column and go to options, then make chart, then line graph. . Print spreadsheet and graph and save in classroom folders, block 1,your name.shroud project. . Answer questions provided on handout . Staple complete project to me and turn in by the end of the class period. Information to Start Out With: . There is 16 grams of C14 as in a piece of shroud of similiar size to start out with before the shroud starts decaying. . You need to find out how much carbon is left after a half of a half life, 1 half life, 2 half live, 3 half lives, and 4 half lives. . Next you need to determine how years go by in one half life. ( Hint Read your material) Then you will need to fiqure out how many will have gone by for each of the half lives indicated above. Chart Format: "Starting #," " # of Half Lives," "Function to get to # Left," "# of C14 left", "Function that compares number left to years elapsed", and finally "years elapsed". As always you need to stay on task or face the consequences. So please stay on task.

