Pre-Tour Classroom Activities

Pre-Tour Classroom Activities

Objectives of the Pre-Tour Activities:

1.)Get the students Enthused and Excited

2.)Get the students to learn some basic background information

Pre-Tour Presentation to get Students Interested:

Background Information & Resources for Radiation & Fission:

The following can be used in any order depending on the teacher’s curriculum needs or goals for this unit.

Possible Assignments:

Play with the fission simulator if the focus is understanding fission. Guided activity and explorations questions are attached ( see )
for the Fission simulator ,
for an Inquiry Activity for Students:
Tips for Teachers: . There are assignments already submitted to PhET by many other educators for different levels especially MS and HS. Look below simulation and click on the >FOR TEACHERS for a list of all the activities. See a sample inquiry lab written by experienced educators at the end of this document!
A possible suggestion for using PhET simulation:

The teacher can introduce the topic of fission by using the PhET simulation on Nuclear Fission as a demo or as a hands-on activity. We suggest doing it as a hands-on activity if you have enough computers for students to pair up together..
For a hands-on activity, split the groups into pairs and have them operate the simulation by following the Inquiry Activity above or develop your own procedure to make sure that all 3 tabs have been used by the groups of students. If you want true Inquiry, let them use the simulation on their own with no guidance and see what they discover on their own!

Of course, this all depends on your students :-)

Once they have used the simulation for 15-20 minutes (depending on your time constraints), have them use the Think-Pair-Share model (or whatever differentiated instruction technique you like) to get them to first think about
what they personally learned from the simulation,
what their partner learned from the simulation by sharing their ideas with their partner,
decide together what to share to the class and then
have an open discussion with the class, led by the teacher, on developing a class list about what they learned from the experience and what questions they still have.

This will generate interest in the upcoming nuclear plant tour so they will have questions ready for the tour guide.

Here is an example of Think-Pair-Share

B. Building the concepts of Nuclear Fission and how it is used in real-world applications.

To get a general idea of what a nuclear reactor is with the introduction of concepts such as fusion, fission, applications and safety, the following videos can be used to enhance their learning. Also, students would need to know the basics of an atom prior to understanding nuclear fission.

These videos are done by Crash Course: Chemistry. Depending upon the experience of your students with chemistry topics related to atomic structure and radiation, different parts could be skipped;

The Nucleus: This is an introduction to the structure of the atom. The students learn about the properties of the nucleus and why they are important to defining what an atom actually is.
Nuclear Chemistry Part 1: This video talks about alpha, beta, and gamma rays and their level of damage.
Nuclear Chemistry Part 2: Fusion and Fission This video talks about mass defect, fusion vs. fission, and applications in the real world.

For more advanced students, we suggest the following videos that could be used as a “Flipped classroom” assignment or any other pedagogical approach that you prefer (for more on Flipped Learning try the following PDF ) before the pre-tour lesson.

SHS 5.3 Fission and Fusion reactions

Fission Reaction with Skittles and Ping Pongs

and Chain Reaction by Pepsi Max

Nuclear Reactor

Again, Think-Pair-Share can be used to generate knowledge learned and questions to pursue.

Before the visit to the MIT nuclear plant, we suggest the creation a google doc form (or equivalent) to gather information from the students through the following questionnaire:

1)Name:

2)Grade level:

3)What is radiation (multiple choice)

a) moving waves

b) moving particles

c) moving particles and moving waves

c) Don’t know

4) Which are the most damaging rays (multiple choice)

a) alpha

b) beta

c) gamma

5) Do you think nuclear plants are safe? (yes/no)

6) List 3 things that make a nuclear plant safe (free response)

7) List 1 to 3 real world applications where the nuclear reactor is used. (free response)

8) Complete: I would like to know more about … (free response)

9) Complete: I do not understand how/what/who…….(free response)

Once student’s answers have been submitted, class can discuss them and make a selection of a set of questions they would like to address on the trip to the MIT nuclear reactor.

3.) Get questions from the students to share with the nuclear lab

From the bank of questions that were developed through class discussion, students (guided by teacher) can decide which questions or topics they would liked to see addressed during the visit to the MIT nuclear facility. These discussions will help filter ideas and questions with the goal to have a more focused interaction between students and tour guide. Teacher can submit this information to the MIT nuclear reactor team a couple of days before the visit.

(*) We suggest these activities are done a couple of days before the visit, to allow for discussion time.

SAMPLE LAB: PhET Nuclear Fission Inquiry Lab

After using this simulation, you will be able to:

· Describe how a neutron can give energy to a nucleus and cause it to fission.

· Explain the byproducts of a fission event.

· Explain how a chain reaction works, and describe the requirements for a chain reaction large enough to make a bomb.

· Explain how a nuclear reactor works and how control rods can be used to slow down the reaction.

Use the Nuclear Fission Inquiry Lab Nuclear Fission PhET simulation at to answer the questions on this page

1. Use the tab called “Fission – One Nucleus” to answer these questions:

a. Try to figure out how you can make U-235 unstable

b. How do you know it’s unstable?

c. Describe what you would do to make U-235 unstable, both in terms of what you see and do in the simulation and what this represents, physically.

d. In your own words, what does “unstable” mean when used to describe Uranium?

2. Imagine that you have many U-235 atoms and you fire a neutron at one of them. What do you think will happen? Explain your prediction using words and drawings.

3. Explore the features of the “Chain Reaction” tab. If you wanted to explain nuclear chain reactions to someone, what would you tell them? Briefly, explain your ideas using appropriate vocabulary and drawings. Make certain that your answer explains why the reaction occurs AND what affects the speed of the reaction.

4. Why is U-235 a good isotope of Uranium for creating chain reactions?

5. Now, you want to make an atom bomb. Use an Internet search to determine which materials are used for nuclear bombs, and use these materials to try to make your bomb. (Remember, a bomb must be transportable – what do you need to do so that it is transportable?) What can you do to make the bomb explode?

6. While using the simulation, what observations have you made that makes nuclear reactions good for bombs?

7. What are at least three things that you need in order to make an effective bomb, and why? Will a nuclear reactor blow up like a nuclear bomb?

8. Explore the features of the “Nuclear Reactor” tab. What is the purpose of the control rods within a nuclear reactor?

Teacher Copy--ANSWERS!!!

PhET Nuclear Fission Inquiry Lab

After using this simulation, students will be able to:

· Describe how a neutron can give energy to a nucleus and cause it to fission.

· Explain the byproducts of a fission event.

· Explain how a chain reaction works, and describe the requirements for a sustained chain reaction large enough to make a bomb.

· Explain how a nuclear reactor works and how control rods can be used to slow down the reaction.

Use the Nuclear Fission Inquiry Lab Nuclear Fission PhET simulation at to answer the questions on this page

1. Use the tab called “Fission – One Nucleus” to answer these questions:

a. Try to figure out how you can make U-235 unstable

b. How do you know it’s unstable?

c. Describe what you would do to make U-235 unstable, both in terms of what you see and do in the simulation and what this represents, physically.

d. In your own words, what does “unstable” mean when used to describe Uranium?

You need to use the neutron gun to fire a neutron at the atom. This changes U-235 to U-236 through the addition of a neutron. U-236 is unstable and quickly fissions into two daughter nuclei. “Unstable” means that the nucleus has too many neutrons to hold itself together. You can tell that the nucleus is unstable because it breaks into two daughter nuclei, and because the energy graph shows that this is in an energetically unstable state (i.e., the split atom is lower energy than the unsplit U-236). There is no magic ratio of neutrons to protons that is always stable – it depends on the particular atom.

2. Imagine that you have many U-235 atoms and you fire a neutron at one of them. What do you think will happen? Explain your prediction using words and drawings.

Student answers will vary. As they will see in the next step, the daughter nuclei from the induced fission of the first U-235 atom will induce fission in the rest of the atoms.

A nuclear chain reaction is when the products of one nuclear fission (i.e., the daughter nuclei from a split atom) prompt the fission of additional fissionable atoms, which prompt the fission of more atoms. The chain reaction only occurs if this process self-perpetuates; that is, enough fissionable atoms are present so that the products of each fission are likely to hit another fissionable atom.

4. Why is U-235 a good isotope of Uranium for creating chain reactions?

U-235 is ideal for creating a chain reaction because it splits into two daughter nuclei. Only one daughter nuclei is necessary to induce fission in another U-235. So, since the number of fission products is more than the number required to induce fission, the chain reaction keeps going.

The bomb must have a containment vessel and include both U-238 and U-235, since in the real world most Uranium is U-238. U-238 is not fissionable, and the chain reaction does not continue with a high ratio of U-238. Thus, weapons-grade Uranium (which naturally contains more U-238) is enriched with U-235.

6. While using the simulation, what observations have you made that makes nuclear reactions good for bombs?

Each nuclear fission releases energy (as can be seen by the energy graph on the Fission: One Nucleus tab). The fission of a small number of atoms can trigger the fission of a large number of atoms, and thus the release of large amounts of energy.

7. What are at least three things that you need in order to make an effective bomb, and why? Will a nuclear reactor blow up like a nuclear bomb?

a. It needs to include some fissionable nuclei (i.e., U-235). Otherwise, there is no chain reaction.

b. Each induced fission must create more daughter nuclei than are needed to create a new fission event (see #4 above).

c. There must be a large enough ratio of fissionable nuclei (i.e., U-235). Otherwise, the chain reaction does not reach all the nuclei. This ratio is reached when each fission creates – on average – more than one daughter nuclei, so that a chain reaction will occur. That means we must have more U-235 than U-238.

d. The U-235 must be densely spaced enough so that the daughter nuclei are likely to hit another U-235 before hitting the container wall or escaping to the outside.

e. Nuclear fission reactors do not blow up like a nuclear bomb, but can get out of control and release too much radiation and heat. A recent nuclear accident in Japan had a partial “meltdown” and released some radiation, but did not blow up!!!

8. Explore the features of the “Nuclear Reactor” tab. What is the purpose of the control rods within a nuclear reactor?

They control the rate of fission of the uranium in the reactor by absorbing neutrons and daughter nuclei. When partially removed, they allow a chain reaction to occur. Thus, the presence of control rods allow the reaction to be slowed or stopped, preventing the nuclear reactor from becoming a nuclear bomb.