Nuclear Reactions WebQuest
Introduction:
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.
Task 1: Atomic Nucleus
1. What are nucleons?
2. Nuclear Makeup. What force holds the nucleus together?
3. Remember that the force is only able to work over very small distances, meaning
that it has a limited range. What is the largest known completely stable nucleus?
**If the strong force is unable to hold the nucleus together then the atom is
radioactive.
4. (Click on neutron) Which subatomic particle determines the isotope of an
element?
5. Who is given credit for discovering the existence of the neutral particle in the
atom in 1932?
(Use textbook chap. 18 sec 1 for next two questions)
6. The ratio of neutrons to protons in the nucleus is related to the atoms stability.
Therefore if the nucleus has too many or too few neutrons compared to protons
it is radioactive.
What is the ratio for stable isotopes of smaller elements?
7. What is the neutron to proton ratio for stable heavy elements?
Task 2: Type of Radioactivity
1. What is radioactive decay?
2. Define one becquerel (Bq).
3. Discovery. Who first discovered radioactivity in 1896?
4. He discovered radioactivity while working with phosphorescent uranium salts
and photographic film trying to determine if the reason it glowed was the same
reason that cathode ray tubes glowed due to X-rays. What are phosphorescent
materials?
5. What other 2 radioactive elements did Marie Curie discovery during further
research?
6. Danger of radioactive substances. Who was the first to discover that
exposure to X-rays could produce burns to the skin?
7. Who was the first to demonstrate the genetic effects of radiation and what was
the date(he would win a Nobel Prize in 1946 for his findings)?
8. What are some of the type of items containing radioactive substances marketed
to the public before the effects of radiation were known?
9. Types of Decay. What are the 3 most common types of radioactive radiation or
radioactive decay emissions.
Read about the types of decay in your textbook Chap 18 or online and
complete the following chart:
Type of
emission
symbol
what consists of
nuclide notation
what happens to
the nucleus
(the cause)
relative speed
relative mass
slow
no mass
Example of
material that
can stop it
Effect on cells
(biological
effect)
10. Decay chains. When an atom is unstable it will give off energy and particles
as it decays - this process is called transmutation. The atom decays as it
works towards becoming stable. The steps that it takes during this
transmutation process is known as its decay series or chain. The decay chain
of Uranium-238 ends with what stable nuclide?
11. Radioactive carbon-14 is constantly being produced today. How does this
happen?
12. Define "half life".
13. Look back at the decay chain for 238U. What is its half life?
14. Which isotope in its decay chain has the shortest half life and how long is it?
Task 3: Nuclear Fission
1.
What is Nuclear Fission?
2.
Draw an example of a Fission Reaction.
3.
What are 2 uses of the energy produced by a Fission reaction?
4.
Nuclear fuels are bombarded by what particles to induce or start their fission?
5.
What is a chain reaction?
6.
A Fission Chain reaction that releases energy at a controlled rate is used in
___________________.
7.
A fission chain reaction that releases energy at very rapid uncontrolled rate is
used in _____________________.
8.
What makes Nuclear Fission a very tempting source of energy for now and the
future?
9.
What is the drawback to this type of energy production?
10. Nuclear or Fissile fuels. What are the two most common isotopes used as
nuclear fuels?
11. Chain reactions. How is the number of neutrons in an "assembly" involved in
creating a "sustained nuclear chain reaction"?
12. Draw an example of a chain reaction.
13. Define "critical mass"?
14. Fission Reactors. What is a nuclear reactor?
15. What are some uses for nuclear reactors?
Inside a nuclear power plant:
Nuclear Power Plant
16. What is referred to as the “rods” in the reactor?
17. When the fuel bundles are lowered into the water, what is the water’s
purpose?
18. What is the purpose of the control rods and how do the work?
19. How is the heat energy produced by the nuclear reaction used to make
electrical power? Give the steps.
Task 4: Nuclear Fusion
1. Define Nuclear Fusion.
2. What happens when two nuclei lighter than iron are fused?
3. What happens when two nuclei heavier than iron are fused?
4. Where does Fusion occur naturally?
5. Draw an example a fusion reaction.
6. Who first observed the fusion of light nuclei and in what year?
Task 5: Nuclear Explosions
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?
List of Nuclear States
1. Of the current nine nations or countries to have successfully produced and
detonated a nuclear weapons, which 5 are known as Nuclear Weapon
States?
2.
What does NPT stand for? And what year did it come into force?
3.
What countries have conducted Nuclear tests and are not parties to NPT?
4.
What is the view currently on Israel?
5.
What is unique about South Africa?
6.
About how many active nuclear warhead exist today, compared to 1985’s
65,000?
7.
When was the first Russian test of a fission weapon?
8.
When was the first test of a fission weapon in the United Kingdom?
9.
When was the first French test of a fission weapon?
10. When was the first test of a fission weapon by China?
11. When was the first test of a fission weapon by India?
12. When was the first test of a fission weapon by Pakistan?
13. When was the first test of a fission weapon by North Korea? What happened?
Task 6: Nuclear Fallout
1. What is nuclear fallout?
2. Local. What percentage of the total bomb debris is deposited on the ground as
"local" fallout?
3. Short term. What does LD50 mean?
4. When referring to radiation, how long a time period is involved for the LD50 for
humans?
5. In the 1950’s, what was set as the LD50 for Gamma rays?
6. Most people become ill after an exposure to how many Grays?
7. Fallout radiation decays relatively quickly. What period of time is needed for
fallout to decay to fairly safe levels for short-time exposure?
8. Fallout protection. Why are fallout shelters no longer maintained in the United
States?
9. What are the two main differences between bomb fallout and fallout from a
reactor accident? Describe them.
Task 7: Radioactive Waste
1.
What is radioactive waste?
2.
Sources of Waste. What are some of the sources of radioactive waste?
3.
Front end. What is waste created from the front end of the nuclear fuel cycle?
4.
Back end. What uranium isotope is found in spent fuel rods?
5.
When dealing with Nuclear power and Nuclear waste, you often hear the term
Proliferation come up. What does this mean? And why is it a concern of
many?
6.
Medical. List some of the radioactive isotopes used in medicine along with its
purpose and half life.
7.
Naturally Occurring Radioactive Material (NORM). Small amounts of what
four radioactive elements are found in coal and its surrounding shale?
8.
Types of radioactive waste. What do the letters "LLW" stand for?
9.
Where does this type of waste come from?
10. What is HLW? Where does this type of waste come from?
Long Term Management of Waste:
13. For each of the following explain the idea for the disposal of nuclear waste and
then give any shortcomings, disadvantages or drawbacks.
• Geologic Disposal
• Transmutation
• Re-use of waste
• Space Disposal
14. What is WIPP and where is it located?
***See if you can find this out: Does SC have any nuclear waste storage sites?
And if so Where?