thursday, february 2nd

Thursday, February 2ndQuick write:1. Take the article from desk2. Read the article3. Questions:

– What is Fission?– What is fusion?– Who is Lise Meitner?

Homework:• Complete the accompanying Review

sheet

SWBAT:• Identify fusion and fission• Label Nuclear Fission and Nuclear Fusion• article reading and discussion

Nuclear Atoms• Fission: binary fission/splitting/biology term : ) – The splitting of an atomic nucleus into two smaller

nuclei having almost the same mass, the missing mass is in the form of energy

• Fusion: to bring together– The joining of two low mass nuclei to form a single

larger nucleus to produce helium and energy

Nuclear Fission– How?• The bombardment of a neutron or nuclear “bullet” to

Uranium-235• Forming Barium-141 nucleus and Krypton-92 nucleus• With the release of 2 or 3 neutrons

– Energy released from Uranium-235 is not great– The neutrons cause the most damage by splitting more uranium nuclei– Known as:

» Nuclear chain reaction:• A continuous series of fission occurrences• Continues until there is no more Uranium-235

– Atomic Bomb• An uncontrolled nuclear chain reaction

Nuclear fission – splitting the atom.

J Deutsch 2003 4

235U + 1n 90Sr + 143Xe + 31n

More neutrons are released to keep the reaction going.

Nuclear Fusion

– How?• Temperatures must reach over a million degrees Celsius• This forms plasma!• Its products form a mass of 1% less than its reactants• The loss of mass is converted to a tremendous amount

of energy• Hydrogen Bomb is result to nuclear fusion.• Fusion requires nuclear fission to stimulate the reaction

artificially• The sun’s energy is powered by fusion

Nuclear fusion – joining small atoms.

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2H + 3H 4He + 1n

Hydrogen atoms combine to form helium in a star.

Friday, February 3rdQuick write:1. Take sheet from desk and article2. Read directions to the

assignment

Homework:• Read your article• Work on your article summary

outline due Wednesday• Article summary and response

due Monday, February 13th, it must be typed!

SWBAT:• Compare fusion and fission• Label Nuclear Fission and Nuclear Fusion• Side effects to radiation• article reading and discussion

Nuclear Fusion– Benefits of fusion:

1. Energy is greater2. Produces less radioactive wastes3. Fuels are more plentiful

– Disadvantages:1. Very difficult to begin, control and maintain2. Temperature requirements are extremely too hot to

manage3. Thermonuclear: reaction that requires a lot of heat

NRC: The Boiling Water Reactor (BWR)

Nuclear Fission

– Benefits:• Controlled fission is used to operate nuclear power

plants• Controlled Nuclear Reaction• The energy is in the form of heat, then used to produce

electricity

– Disadvantages:• Does not create as much energy as fusion

Monday, February 6thQuick write:1. Read the article2. What is the function of the magnetic

field?3. How is the plasma created?4. What is the tokamak?Fusion energy: The tokamakHomework:• Web Quest due Friday• Read your article• Work on your article summary outline due

Wednesday• Article summary and response due Monday,

February 13th, it must be typed!

SWBAT:• Compare fusion and fission• Label Nuclear Fission and Nuclear Fusion• different forms of ionization management• article reading and discussion

Name ___________________________

Web Quest

http://kentshillphysics.net/nuc5.htmAnswer the following:1. Describe what is a chain reaction.2. What is the role of a control rod?3. Explain a typical fission reaction and write out an equation for

the reaction.4. What can fission be used for in your life?5. Explain a typical fusion reaction and write out an equation for

the reaction.6. Sketch and label each segment of a nuclear power plant

Tuesday, February 7thQuick write:1. Take work sheet from desk 2. Label the diagram

Homework:• Web Quest due Friday• Read your article• Work on your article summary outline due

TOMORROW• Article summary and response due Monday,

February 13th, it must be typed!

SWBAT:• different forms of ionization management• describe each segment of an nuclear power plant

1. Energy released in a nuclear reaction (fission or fusion) comes from the fractional amount of mass converted into energy.

2. Nuclear changes convert matter into energy.

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E=mc2

• The energy released is equal to the mass lost (m) times the speed of light (c) squared.

• Relationship between mass and energy.

• Developed by Albert Einstein

Speed of light: 299,792,458 meters per sec

Mass Deficit

Detecting and Managing Radioactivity

1. Electroscope– A metal rod with two thin metal leaves at one end to

detect radiation.How it works!

• If a negative charge is detected the metal leaves separate• Because radioactive substances remove electrons, the molecules

in the air become more positive• These positive charged molecules are sensed by the electroscope

which pulls the negatively charged leaves away from each other.

• The Electroscope

Detecting and Managing Radioactivity . . . .

2. Geiger Counter– 1928: Hans Geiger designed an instrument to measure

and detect radiation– In the presence of radiation it produces an electrical

currentHow it works!

• There is a tube filled with gas (argon or helium) • If radiation enters the tube it will remove electrons from the

gas atoms becoming cation atoms• This sets off a current which can be measured

Other Detection Devices

Geiger Counter

J Deutsch 2003 16

Detecting and Managing Radioactivity . . . .

3. Cloud Chamber– 1911: Charles Wilson designed the cloud chamber

which enables you to visually see the path of ionization as well as photograph it

How it works!• The container is glass or plastic sitting on dry ice• Once the radiation enters the chamber it will interact

with condensed alcohol seeds.• You can see a trail of the seeds forming

The Cloud Chamber

Detecting and Managing Radioactivity . . . .

4. Bubble Chamber– 1952: Donald A. Glaser created this vessel– 1960: He received a Nobel Prize for his inventionHow it works!• A large chamber uses a superheated transparent liquid

(often liquid hydrogen is used) to react with charged particles to detect radiation.

Wednesday, February 8thQuick write:1. Take a sheet from the desk 2. Read the article and answer the

following:1. What is the reading about?2. How is it related to science and

history?3. How do you feel about the reading?

Homework:• Web Quest due Friday• Test Moved to Next Wednesday!• Article summary and response due

Monday, February 13th, it must be typed!

SWBAT:• Place the parts of each nuclear equation in order.• Describe each segment of an nuclear power plant.• Identify each segment of a nuclear power plant.

Wednesday, February 8thQuick write:1. Take a sheet from the desk 2. Read the article and answer the

following:1. What is the reading about?2. How is it related to science and

history?3. How do you feel about the reading?

Homework:• Web Quest due Friday• Test Friday!• Article summary and response due

Monday, February 13th, it must be typed!

SWBAT:• Place the parts of each nuclear equation in order.• Describe each segment of an nuclear power plant.• Identify each segment of a nuclear power plant.

235U + 1 neutron >>>> 2 neutrons + 92Kr + 142Ba + ENERGY

235U + 1 neutron >>>> 2 neutrons + 92Sr + 140Xe + ENERGY

2H + 3H ----> 4He + n2H + 3H ----> 4He + n2H + 3H ----> 4He + n

Review of Nuclear Reactions

• Basic Nuclear Fission

What is a Nuclear Reactor?

• It is a controlled system that holds sustainable nuclear chain reactions.

Usages:• generating electricity• moving aircraft carriers and submarines• producing medical isotopes for imaging and

cancer treatment• research

What is a Nuclear Reactor?

What are the parts of a Nuclear Reactor?

1. Control rods:– Extra neutrons are absorbed and/or soaked up – When the rods are lowered: slows down the process– When the rods are raised: speeds up the process

2. Core:– Contains the nuclear fuel in the rods, using U-235, this is the site of nuclear

fission3. Concrete Casing:

– Acts as a barrier to protect workers from the radiation produced4. Moderator:

– Enables the neutrons to slow down to a speed where nuclear fission can take place in the nucleus.

5. Generator:– Site where the heated up water spins the generator to produce a source of

electricity to power your house!

What takes place after the Fuel is used?

1. The fuel now has nuclear waste.2. The U-235 has transformed into a series of isotopes of

almost every transition metal on the periodic table!3. The fuel originally contained U-235, oxygen and steel.4. It remains for thousands of years! Yikes!5. Where? It is stored under water until the radiation

decays to a level that can be maintained.6. Now what? It is contained in concrete storage casks

either deep under the Earth or used in recycling.

Thursday, February 9thQuick write:1. Complete the following equations:

_____+ 1 neutron >> _______+ Kr-92 + Ba-142 + _________ + 3H ----> _____ + n + energy

2. Label which one is fusion and which equation is fission.3. Which reaction powers the sun?4. Which reaction causes radioactive waste?Homework:• Web Quest due Friday• Test Next Wednesday• look online for test topics!• Article summary and response due Monday, February 13th!

SWBAT:• Identify different equations of nuclear reactions• Describe each segment of a nuclear power plant.• Identify the topics for the test.

Nuclear Equations

FUSION:

2H + 3H ----> 4He + n

FISSION:U-235 + 1 neutron >> 2 neutrons + Kr-92 + Ba-142 + ENERGY U-235 + 1 neutron >> 4 neutrons + Sr-92 + Xe-140 + ENERGY

What is ionization?

• Is a process of absorption of radiation as it penetrates through material

• Changes the electrical balance of an atom• Causes ions in the material and partial or all

amounts of radiation to be lost.• Two types of ions:– Cation– Anions

What is the Theory of Relativity?

• Mass and energy can be converted into each other.

• This supports the Theory of Conservation of Energy:– If matter is destroyed then energy is created! – If energy is destroyed than matter is created!

• Therefore, the total amount of energy and mass is still conserved!

• This supports the Law of Conservation of Energy, energy cannot be created nor destroyed by ordinary means.

Friday, February 10thQuick write:1. Take a lab2. Define Radiation, Convection and Conduction.

Homework:• Test Next Wednesday• look online for test topics!• Article summary and response due Monday, February 13th!

SWBAT:• Describe Radiation, Conduction and Convection.• Observe radiation, conduction and convection.

Monday, February 13thQuick write:1. Complete the Practice Test Question Worksheet.2. Take out your typed article

Homework:• Test Wednesday• look online for test topics!

SWBAT:• Observation of radiation, conduction and convection.

Tuesday, February 14thQuick write:1. Use the image to the

right and answer the following:

1. Write down 3 ways you can identify a Nuclear Fusion Reaction.

2. Write down 3 ways you can identify Nuclear Fission Reaction.

SWBAT:• Complete lab on Observation of radiation, conduction and convection.• Identify the parts of the nuclear reactions.

239 Pu + n---> 233 U + 3n+ 4 He + Energy1. One Large nucleus forms two smaller nuclei2. Neutron and one atom found as a reactant 3. U or Pu as a reactant

2 H + 3 H---> 4 He + 1n + Energy1. Two smaller nuclei combining to form One larger nucleus2. Two Hydrogen atoms as reactants3. One large Helium atom as a product

Homework:• Test Wednesday!• look online for test topics!• Only the 3 lab stations and Lab question Packet due Friday!

• The following slides were not covered

Other uses of radioactive isotopes

• Radioactive Dating:–Geological dating: U-238 occurs naturally in

rocks, used to age mountains• Dating Live Matter:–Organisms that were once alive, Carbon-14 is

used to date wood, bone, animal skin or fabric.• Irradiated food – gamma rays kill bacteria, yeast and mold for

storage for longer timeJ Deutsch 2003 36

Other uses of radioactive isotopes

• Radioactive tracers–Carbon-14 is used to follow a chemical

reaction to trace for a tumor.• Medical isotopes– Technetium-99: pinpointing brain tumors– Iondine-131: diagnosis and treatment of

thyroid disorders–Radium and Cobalt-60: treatment in cancer

Risks in Radioactivity• Biological Damage:– Damage and destroy cells forming burns, cataracts,, cancer

• Long term Storage– Unknown future outcome!

• Accidents:– Fuel and wastes escape from nuclear reactors– 1986: Chernobyl in Ukraine was destroyed by an uncontrolled

chain reaction, winds spread wastes all throughout Europe– March 2011: Fukashima, Japan, nuclear reactor meltdown and

nuclear wastes lost following the Tohoku earthquake and tsunami