Nuclear Reactions WebQuest


As a "chemist", you can easily alter the electron arrangement in the outer energy level of atoms. But you cannot change the nucleus of an atom. Almost any change in the nucleus of an atom will change it from one element to another. This violates one of the basic laws of chemistry - that atoms are neither created nor destroyed in chemical reactions.

The same is not true in nuclear reactions. This type of reaction occurs naturally every day, with the decay of radioactive elements. Even though large amounts of energy of involved, so few atoms actually decay at any one time that there is no immediately observable change. However, over an extended period of time, the energy released can be enough to damage living things.

Nuclear reactions are more physics than chemistry. Because of the large amounts of energy needed to change the atomic nucleus, a device known as a particle accelerator is needed to produce an artificial nuclear reaction.

WebQuest Tasks

Task 1: The Atomic Nucleus

Use this Atomic Nucleus webpage to answer the following questions.
  1. What are nucleons?
  2. The nucleus is about 25 orders of magnitude smaller than the whole atom. What macro-world example is given to visualize this difference in size?
  3. What nuclear particle determines the isotope of an atom?
  4. Wolfang Pauli proposed the existence of a particle he called a "neutron" in 1930. What name did Enrico Fermi change it to in 1931?
  5. Fermi's new name means what in Italian?
  6. What three forces are unified by the standard model of particle physics?
  7. What numbers of neutrons and protons are listed as particularly stable?
  8. What are the two most common particles created in the big bang that are still easily observable today?
  9. Where were most of the heavy elements (heavier than hydrogen) we see today created?
  10. Nuclear fusion only releases energy when elements that are lighter than what element are involved?

    Use this Magic Number page to answer the next five questions.

  11. What are the nine magic numbers?
  12. The longest-lived known isotope among elements between 110 and 120 lasts how many seconds?
  13. The number 184 was once thought to be a magic number. Why is it no longer considered to be one?
  14. What term is used to indicate a nucleus whose neutron number and proton number are both equal to one of the magic numbers?
  15. In the "shell model" for a nucleus, magic numbers are the numbers of nucleons at which a shell is what?

Task 2: Types of Radiation

Use this Radioactive Decay webpage to answer the following questions.
  1. What is radioactive decay?
  2. Define one becquerel (Bq).
  3. What is an "induced" nuclear reaction? Give two common examples.
  4. What are phosphorescent materials
  5. Who was the first to discover that exposure to X-rays could produce burns to the skin?
  6. Who was the first to demonstrate the genetic effects of radiation?
  7. The decay chain of Uranium-238 ends with what stable nuclide?
  8. Radioactive carbon-14 is constantly being produced today. How does this happen?
  9. Define "half life" and give the symbol used for it.

Task 3: Nuclear Fission

Use this Nuclear Fission webpage to answer the following questions.
  1. What are the two most common nuclear fuels?
  2. Nuclear fuels are bombarded by what particles to induce their fission?
  3. Why do heavy elements neclei contain proportionally more neutrons than light element nuclei?
  4. What does it mean if an isotope is "fissionable"?
  5. What does it mean if an isotope is "fissile"?
  6. How is the number of neutrons in an "assembly" involved in creating a "sustained nuclear chain reaction"?
  7. Define "critical mass"?
  8. What is a "breeder reactor"?
  9. What is a "power reactor"?

Task 4: Nuclear Fusion

Use this Nuclear Fusion webpage to answer the following questions.
  1. What happens when two nuclei lighter than iron are fused?
  2. What happens when two nuclei heavier than iron are fused?
  3. Who first observed the fusion of light nuclei and in what year?
  4. The collision of two nuclei to produce nuclear fusion produced a LOT of energy. There is only one type of collision that is known to produce more energy. What is it?
  5. The strong nuclear force can easily overcome the electrostatic force that pushes like charges apart. So why is so much energy needed to bring to positive nuclei together to fuse?
  6. Gravity is a force strong enough to confine fusion fuels close enough for ignition. Why can't we make a fusion reactor using gravity?
  7. The "proton-proton chain" produces most of the energy in stars the size of our Sun and smaller. What particles fuse in this reaction?
  8. What is produced by the proton-proton chain?

Task 5: Nuclear Explosions

Use this Nuclear Explosions webpage to answer the following questions.
    1. On what month, day and year was the first man-made nuclear explosion?
    2. What was the "name" of the bomb dropped on Hiroshima, Japan?
    3. When was the first Russian test of a fission weapon?
    4. When was the first test of a fission weapon in the United Kingdom?
    5. Who or what was Ivy Mike?
    6. When was the first French test of a fission weapon?
    7. When was the first test of a fission weapon by China?
    8. When was the first test of a fission weapon by India?
    9. When was the first test of a fission weapon by Pakistan?
    10. When was the first test of a fission weapon by North Korea? What happened?

Task 6: Neutron Bomb

Use this Neutron Bomb webpage to answer the following questions.
  1. Neutron bombs are ERWs. What do the letters "ERW" stand for?
  2. In what year did the US dismantle its last remaining neutron bomb?
  3. What is the tactical military reason for using a neutron bomb?
  4. What does of radiation were neutron bombs intended to deliver?

Task 7: Nuclear Fallout

Use this Nuclear Fallout webpage to answer the following questions.
  1. What is nuclear fallout?
  2. What percentage of the total bomb debris is deposited on the ground as "local" fallout?
  3. What does LD50 mean?
  4. When referring to radiation, how long a time period is involved for the LD50 for humans?
  5. Most people become ill after an exposure to how many Grays?
  6. Fallout radiation decays relatively quickly. What period of time is needed for fallout to decay to fairly safe levels for short-time exposure?
  7. Why are fallout shelters no longer maintained in the United States?
  8. What are the two main differences between bomb fallout and fallout from a reactor accident?

Task 8: Radioactive waste

Use this Radioactive waste webpage to answer the following questions.
  1. What is radioactive waste?
  2. Other then industry directly related to nuclear reactions, what industry has produced eight million tons of radioactive wastes over the past 20 years?
  3. Uranium dioxide (UO2) ore is refined into "yellowcake". What is the chemical formula for yellowcake?
  4. Uranium hexafluoride is "enriched" to increase its U-235 content from 0.7% to what percent?
  5. What is the U-235 content of depleted uranium (DU)?
  6. What are two common uses for depleted uranium?
  7. What uranium isotope is found in spent fuel rods?
  8. Small amounts of what four radioactive elements are found in coal and its surrounding shale?
  9. What do the letters "LLW" stand for?
  10. Which elements are referred to as "transuranic"?
  11. What is vitrification?
  12. What do the letters "AFRS" stand for?
  13. What is WIPP, and where is it located?

Task 9: Accidents & Regulation

Explore these web pages on your own.

Conclusion to the WebQuest:

There has not been a new nuclear power plant built in the United States in thirty years. In fact, the last nuclear powerplant under construction was not finished because of court challenges by a citizens' political action group. This was the PSO Black Fox Nuclear Power Plant in Oklahoma.

A new federal energy bill was signed in 2005 that included incentives for new construction of nuclear power plants in the United States.

Should the United States build more nuclear power plants?

WebQuest Application: