Summary

In this lesson, students will learn about the development and application of radiocarbon dating through an article reading. There are a series of activities to help promote literacy in the science classroom related to the reading. This lesson could be easily used as plans for a substitute teacher, as most of the activities are self-guided.

Grade Level

High School

NGSS Alignment

This lesson will help prepare your students to meet the performance expectations in the following standards:

• HS-PS1-8: Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
• Scientific and Engineering Practices:
  • Using Mathematics and Computational Thinking
  • Constructing Explanations and Designing Solutions
  • Engaging in Argument from Evidence
  • Obtaining, Evaluating, and Communicating Information

Objectives

By the end of this lesson, students should be able to:

• Understand how carbon dating works.
• Learn the concept of half-lives.
• Recognize the factors that contribute to isotopes.

Chemistry Topics

This lesson supports students’ understanding of:

• Nuclear Chemistry
• Radioactive Isotopes
• Half-life
• Carbon Dating

Time

Teacher Preparation: 10 minutes
Lesson: Approximate times for students to complete each activity in the lesson:

• Anticipation guide: 10 minutes
• Reading: 20 minutes
• Timeline: 10–15 minutes
• Graphic organizer and writing: 15–20 minutes
• Nuclear equations: 20–30 minutes
• Jigsaw summary: 15–30 minutes

Materials

• Reading document and desired handouts to accompany the reading.
• A computer with internet access for the Jigsaw summary.

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

Background:

• This lesson plan was originally developed through the American Chemical Society’s National Historic Chemical Landmarks Program. Under this program, ACS grants Landmark status to seminal achievements in the history of the chemical sciences and provides a record of their contributions to chemistry and society in the United States.

Lesson Overview:

The lesson includes multiple components as outlined individually below. The Reading is essential for all of the activities. Teachers can choose to do one or all of the included activities. Student handouts and corresponding answer keys are provided for each item described below:

• Activity: Anticipation Guide
  • Have students identify whether they agree or disagree with the ten statements. After they complete the reading, they can adjust their answers and rephrase “disagree” statements so they read true.
  • Instead of using the Anticipation Guide, consider this idea to engage students:
    • Ask students to share when they think the method of radiocarbon dating was developed and what technical obstacles the scientist who developed it might have had to overcome.
    • After this discussion, invite students to read the article to find more details about how Willard Libby developed the method of radiocarbon dating and how the method can be used.
• Reading: Radiocarbon Dating and Willard Libby
• Activity: History Exercise
  • Students are asked to develop a timeline by arranging events in chronological order. Students could do this before the reading and then adjust the order of events once they read the article and learn more about the discovery of ¹⁴C.
• Activity: Graphic Organizer and Writing Assignment
  • Students sort artifacts into those that can and can’t be dated using radiocarbon dating methods, then they identify how different kinds of scientists might use radiocarbon dating. Finally, they identify challenges and assumptions that Libby had to make when doing his work.
• Activity: Nuclear Equations
  • Students write nuclear equations for the formation and decay of ¹⁴C and extend that understanding to other types of nuclear equations.
• Activity: Jigsaw Summary
  • After reading the article, students work in groups on one of the suggested projects, then each group summarizes their results to share with the class in a 1-minute presentation

• Related classroom resources from the AACT library that may be used to further teach this topic:
  • Activity: The Demise of Frosty
  • Activity: Why are Some Isotopes Radioactive?
  • Activity: Radiological Applications of Isotopes
  • Activity: Using Stable Isotopes to Determine Material Origin
  • Activity: Graphical Analysis of Nuclear Decay
  • Activity: Radioactive Decay and Seafloor Data

• ACS Reactions video:
  • What are Isotopes?

• Other useful links:
  • National Historic Chemical Landmark: Willard Libby and Radiocarbon Dating