Science Lesson: Cold Fusion?

Abstract
During this lesson, students will be introduced to fusion. Having studied fission and learned about mass defect, students are now prepared to learn about fusion. Students should learn that fusion is what provides the sun with its energy. They should also realize that fusion has been duplicated on earth, but not at low enough temperatures to be practical. This is why the search is now for “cold” fusion, which is basically fusion at low enough temperatures to be practical as an energy source.

Purpose –The purpose of this lesson is for students to apply their knowledge of relativity and nuclear radiation to the concept of cold fusion.

Objectives
Students will be able to:
1. Differentiate between fusion and fission.
2. Know how the sun generates its energy.
3. Understand the challenges of cold fusion.

National Science Education Standard:
Content Standard B-Physical Science
STRUCTURE OF ATOMS
• The nuclear forces that hold the nucleus of an atom together, at nuclear distances, are usually stronger than the electric forces that would make it fly apart. Nuclear reactions convert a fraction of the mass of interacting particles into energy, and they can release much greater amounts of energy than atomic interactions. Fission is the splitting of a large nucleus into smaller pieces. Fusion is the joining of two nuclei at extremely high temperature and pressure, and is the process responsible for the energy of the sun and other stars.

Content Standard E-Science and Technology
UNDERSTANDINGS ABOUT SCIENCE AND TECHNOLOGY
• Science and technology are pursued for different purposes. Scientific inquiry is driven by the desire to understand the natural world, and technological design is driven by the need to meet human needs and solve human problems. Technology, by its nature, has a more direct effect on society than science because its purpose is to solve human problems, help humans adapt, and fulfill human aspirations. Technological solutions may create new problems. Science, by its nature, answers questions that may or may not directly influence humans. Sometimes scientific advances challenge people's beliefs and practical explanations concerning various aspects of the world.

Related and Resource Websites

http://www.wired.com/wired/archive/6.11/coldfusion.html (article on cold fusion)
http://observe.arc.nasa.gov/nasa/exhibits/stars/star_6.html (fusion description)

Activity

Day 1

1. As students enter the classroom, have these questions posted on the board for them to answer:

a. Define fission.
b. What are some of the products of fission? What uses do we have for fission?
c. Where does fission get its energy?

2. Go over the answers to these questions. Students should have a general knowledge of fission as the splitting of large atoms, usually uranium. They should also have some idea of the products of fission, generally smaller and more stable atoms, energy, and radiation. Make sure that the term mass defect is discussed, which is the loss of mass that takes place in a nuclear reaction.

3. Have students read the article from the website listed in the related and resource websites. Discuss the article with the class. Hopefully, some questions about what cold fusion is will come up.

4. The second website gives an explanation of fusion. This is a fairly technical description so it should be discussed as a class, not individually. The main idea is to realize that this is the opposite of fusion. Instead of large atoms being split, fission is small atoms being combined to form larger ones. There is still a mass defect, so there is still energy being generated. Most importantly, there is no waste produced!

5. Allow the rest of the class for students to research cold fusion. They should be looking for some of the problems associated with cold fusion and how successful it’s been. Also, they should understand why the term cold fusion is used. Why are we aiming for cold fusion?

Closure
Finish the lesson by asking students their opinion on cold fusion. Is it just a pipe dream or does it hold the secret for our future energy consumption? Students should respond on a half-sheet of paper. Allow them to veer from their usual factual writing for this class. Ask them for a fictional depiction of what life would be like if we could learn to harness the power of cold fusion.

Embedded Assessment
Closing writing assignment: Although it is a fictional composition, its content can be assessed for understanding of the lecture presented.

Embedded Assessment