Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.
-
Upload
vincent-martin -
Category
Documents
-
view
246 -
download
5
description
Transcript of Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.
![Page 1: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/1.jpg)
Unit: Nuclear Chemistry
Fission, Fusion, and Applications of Nuclear Chemistry
Day 4 –
Notes
![Page 2: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/2.jpg)
After today you will be able to…
• Describe what happens in a nuclear chain reaction.• Differentiate between fission
and fusion reactions.• Identify examples of how
radioisotopes are used in everyday life.
![Page 3: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/3.jpg)
Recall, during transmutations an atom can be converted into a different atom through radioactive decay or by bombarding a nucleus with particles.Today, we will focus on the
latter by learning about fission and fusion.
![Page 4: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/4.jpg)
Nuclear FissionFission: occurs when a nucleus is split into smaller pieces.• This process begins by colliding a
nucleus with particles such as neutrons.
• The resulting nucleus is highly unstable and decays.
• This causes a chain reaction where particles emitted from the initial reaction bombard other nuclei, causing them to break apart.
![Page 5: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/5.jpg)
Example: Uranium-235
ENERGY
n10 U235
92
U23692
n10
n10
n10
Kr9136
Ba14256
A neutron collides with the U-235 atom.
The U-236 atom is unstable and decays.
U-236 is formed.
The neutrons released from the decay of U-236 will collide with
other U-235 atoms,
repeating this process all over again (chain
reaction).
![Page 6: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/6.jpg)
Nuclear Fission• Uranium-235 and
Plutonium-239 are the only fissionable isotopes.
• These reactions release a large amount of energy.
![Page 7: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/7.jpg)
Nuclear FusionFusion: occurs when nuclei combine (or fuse together) to produce a new nucleus of greater mass.• Example: Production of
energy from the sune0
+1H11 H
e42 energ
y++4 2
![Page 8: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/8.jpg)
Nuclear Fusion• Releases far more
energy than fission reactions.
• These reactions require very high temperatures in order to occur (~40,000,000°C).
![Page 9: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/9.jpg)
Real-World Applications: C-14 Dating
Scientists often find the age of an object that was once living by measuring the amount of carbon-14 it contains.• Recall, C-14 has a half-life of
5730 years.• This is its nuclear decay:
C146 N14
7 e0-1+
![Page 10: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/10.jpg)
Real-World Applications: C-14 Dating
• All living things contain C-12 and C-14 in a fixed ratio.
• Once an organism dies, the ratio of C-14:C-12 changes, which allows archeologists to estimate its age.
![Page 11: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/11.jpg)
Real-World Applications: C-14 Dating
• The most accurate way to examine the C-14 content is through use of a mass spectrometer.
• First, the carbon in the sample must be converted into graphite or carbon dioxide.―This is can be done by burning a
portion of the sample.
![Page 12: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/12.jpg)
Real-World Applications: C-14 Dating
• The sample is then injected into a mass spectrometer and ionized.
• Due to the different masses of carbon having different angles of deflection, a scientist can count the individual C-14 atoms in the sample.
![Page 13: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/13.jpg)
Mass Spectrometer:
![Page 14: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/14.jpg)
Real-World Applications: U-238
But what if all of the C-14 in a sample has decayed or the sample is non-living?• Similar to carbon-14, uranium-
238 is used to date specimens.• Uranium is naturally found in
most rocks, seawater, and in Earth’s crust.
• It has a half-life of 4.5 billion years.
• U-238 is specifically used in dating rocks and fossils.
![Page 15: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/15.jpg)
Real-World Applications: I-131
Radioisotopes can be used to diagnose medical problems or treat diseases.• Specifically, iodine-
131 is a radioisotope given to patients to check for abnormal thyroid function.
• Patients are given a drink containing the radioisotope (Na131I).
![Page 16: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/16.jpg)
Real-World Applications: I-131
• Since the thyroid extracts iodide ions from the bloodstream, the ions are absorbed and its radioactivity is used to create an image on a screen.
• From the image, doctors can examine the amount of iodine absorbed and determine if a person has hyperthyroidism or thyroiditis.
![Page 17: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/17.jpg)
Real-World Applications: Co-60
The strong penetrating power of gamma rays allows it to be useful in the treatment of cancer.• Cobalt-60, which is
produced in particle accelerators, emits both beta and gamma radiation.
![Page 18: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/18.jpg)
Real-World Applications: Co-60
• The Co-60 is placed into a gun that is used to direct the radiation to where the tumor is located.
• The cells of the tumor are destroyed and it decreases in size.
• However, gamma radiation can also destroy healthy cells making those treated very ill.
![Page 19: Unit: Nuclear Chemistry Fission, Fusion, and Applications of Nuclear Chemistry Day 4 – Notes.](https://reader035.fdocuments.us/reader035/viewer/2022081421/5a4d1b2c7f8b9ab0599996ee/html5/thumbnails/19.jpg)
Questions?Begin
WS4