Transcription 1 Science 8: How long will it take for atoms of the radioactive parent Carbon to completely decay to the stable daughter isotope Nitrogen? Relative dating gives an approximate age of something compared to some other event in history. Scientists can tell that the item is older or younger than certain events in time, but cannot give an exact age of the item.
Relative dating is common when comparing layers of rocks in different regions, and figuring out which fossil is older by comparing the rock layers the fossils are in. Absolute dating gives an actual date in history that the item was formed or died. The most common type of absolute dating for geologic material is. A rock containing a radioactive element can be dated by measuring how much of the element remains.
Radiometric dating methods give absolute ages ranging from decades to billions of years. Radioactive elements are unstable and decay into other materials at a known, fixed rate through radioactive decay. Different radioactive elements have different rates of decay. Each radioactive isotope has a characteristic, fixed, half-life.
The is the amount of time it takes for half of the radioactive element to decay or change into another element. Half-lives of elements can range from microseconds to hundreds of billions of years, depending on the isotope. Start with pennies. Each penny represents an atom in the radioactive element Carbon Dump out all of the pennies and spread them out on the table. Remove all the coins that show tails to the side.
These are atoms that have decayed and are no longer radioactive. Record the number of pennies with heads in the table below. These represent atoms that are still radioactive. Put the pennies that had heads up back in the container, mix them, and spread them out on the table and repeat the above process until all the pennies are gone or until you have completed 15 trials.
Graph the data in your data chart on the graph provided on the back. Enter your data into the master spreadsheet to chart an all class average. Which data is more reliable: Explain why with a super sentence. The independent variable always goes on the X or Y axis circle one The dependent variable what I am measuring as a result is: Look at the scoring guide before you start to answer these questions!
Write complete and thorough answers on your own paper, and staple your answers to this sheet. What is the difference between absolute dating and relative dating? Give an example of each. What is the half-life of your atoms of Carbon? How many flips did it take for half of your Carbon to decay? If each flip represents years, how many years would it have taken for all of your Carbon pennies to become Nitrogen pennies? Do you accept or reject your hypothesis?
Be sure to restate your hypothesis before you accept or reject it. Study the chart that shows the half lives of various elements. Most of these elements can be found in rocks all over the Earth. Why would scientists want to use more than one type of element to determine the age of a rock?
Why aren t they satisfied with just using one element? Based on radiometric dating, the oldest rocks scientists have found on Earth are 4. Why might some rocks be 4. Think about the rock cycle and use the names of the different types of rocks in your answer!
Level 3 and Honors question: Keeping in mind that scientists continue to gather information about rocks using radiometric dating, why are scientists interested in studying rocks from asteroids, the moon, and other planets?