Isotope Revolution

When geologists and other scientists investigate the planet (say, a rock from a particular site) they often look at the isotopes – varieties of the same type of atom that differ in the number of neutrons they have – to help determine how old the sample is, where it came from and how it was made. This unit helps students understand what isotopes are and what they tell us, as well as some of the logic and math behind the science. The activities use easy-to-obtain materials that are quick to set up.

Lessons

• Isotopes for Radiometric Dating
  This activity explains isotopes and how they are used in radiometric dating – a technique measuring how old something is based on a knowledge of how quickly its isotopes decay. Students will explore the different types of isotopes used, get a better understanding of what a half-life is and calculate percentages of parent-daughter pairs of isotopes.
• Magnetic Reversal and Radiometric Dating
  This activity helps students learn about plate tectonics through field work that has been done on the Mid-Atlantic Ridge, a mountain range under the Atlantic Ocean. They study the ridge’s makeup to determine its age and signs of the magnetic reversal of the Earth’s poles.
• Using Normalized Isotope Ratios to Date Rock Samples
  Students learn what it means to “normalize” isotope ratios, then use this technique to determine the age of sample rocks. Students will also develop their graphing skills by learning how to normalize data in order to generate linear graphs from random data points.
• Determining the Type of Isotope Decay
  Not all radioactive decay is created equal! Here's an activity that will teach students the ABCs – or should we say the alpha-betas – of decay.

For more information contact Jose Sanchez at sanchez@magnet.fsu.edu or (850) 645-0033.