Summary

In this lesson, students will watch a video and answer questions about isotopes. They will learn about the discovery of isotopes, the difference between chemical and nuclear reactions, different kinds of radioactive decay, and some uses of radioactive isotopes.

Grade Level

Middle School, High School

NGSS Alignment

This activity 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.

Objectives

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

• Define isotopes and explain the differences and similarities in subatomic particles for isotopes of the same element.
• Explain the difference between a chemical reaction and a nuclear reaction.
• Describe the changes that occur in an atom in three types of nuclear decay.
• List uses for radioactive isotopes.

Chemistry Topics

This lesson supports students’ understanding of:

• History of Chemistry
• Atomic number
• Mass number
• Subatomic particles
• Isotopes
• Radioactive isotopes
• Alpha/beta/gamma decay

Time

Teacher Preparation: minimal

Lesson: 10 minutes

Materials

• What are Isotopes? Video
• Student handout
• Computer and projector with sound and internet access

Safety

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

Teacher Notes

• The “What are Isotopes?” video is part of the ACS video series Chemistry Basics. The entire series can be found here.
• The running time of this video is about four minutes. It goes through information pretty quickly, so you may want to pause the video at certain points or play the video through twice.
• This video is intended for students to watch, and for teachers to integrate into their curriculum.
• The student questions/answers are presented in sequential order in the video.
• An answer key has also been provided for teacher reference.