Applied Chemistry
Name _____________________________
Nuclear Unit
Period _______ Date _________________
I. Radioactivity
A. Discovery
1. In 1896, Becquerel noticed that a piece of _______________________ ore, called
pitchblende, exposed a piece of photographic film.

Uranium gave off invisible rays called _______________________ rays.

Uranium is ________________________________________
2. Pierre and Marie Curie (1903): Shared the
in chemistry with
Becquerel.

They discovered 2 new radioactive elements,
1. Marie called Radium the “
native
and
.
” element and Polonium she named for her
.
3. Radioactivity is the release of particles, energy, or both from the ______________ of an atom.

Natural radioactivity is found on the
.
o Everyone receives background radiation at low levels from

________________________________________________,

________________________________________________,

________________________________________________, and

________________________________________________.
o Exposure to radiation _________________ make you or anything else radioactive

___________________ radioactivity is produced in the lab
B. Types of Radiation
1. Energy

Nonionizing radiation is radiation with ____________ energy.
o Examples: ____________________________________________,
____________________________________________, and
____________________________________________.

Ionizing radiation is radiation with _____________ energy.
o Examples: ____________________________________________,
____________________________________________, and
____________________________________________.
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2. Particles released from the ________________________ of an atom

Examples: _____________________ and _______________________ particles
3. Characteristics of Radiation
Type
Symbol
Composition
Penetration
Stopped by …
alpha particle
beta particle
gamma ray
C. Exposure and Uses of Radiation
1. Radon is a decay product of ______________________ found in the soil or bedrock.

This is _______________________ radioactivity.

Radon is a colorless, odorless __________.

Some radon produced in the soil dissolves in __________________________________.

Many houses have _______________________ in the foundation and basement floors
that permit radon to collect and concentrate.

Most radon enters your body by ___________________________________________.

Radon decays by alpha emission to produce _____________________,
_____________________, and ____________________. These are heavy metals that are
not exhaled and produce damaging
particles in the body.

Radon in your home ___________ be checked by you.

Increased ______________________________ and ___________________________
cracks in the floors are 2 ways you can reduce radon exposure.
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2. Smoke detectors use ______________________________
as the ionizing source

Americium emits ___________________ particles.

Special _________________________ of smoke
detectors is required.
3. Radioactive Dating

Used for determining the age of previously _______________________ material.

For material up to 25,000 years old, ___________________________ is used.

For material over 25,000 years old, ____________________________ is used.
4. Some EXIT Signs use tritium or _____________________________ instead of electricity.

The tritium gas is contained in sealed glass tubes. The insides of the tubes are lined with a
____________________. Low-energy _______________ particles (electrons) emitted by
the tritium bombard the phosphor, causing it to _______________.
5. Agricultural and Consumer Product Use

Many everyday products and food are treated to kill ______________________ and
_______________________.

Examples: _______________________
____________________________
_______________________
____________________________

Products are irradiated with ______________________ rays from __________________,

Irradiated products are not ___________________________________.
6. Medical Uses

Diagnostic Tools using radioisotope-tracer studies

Radioisotopes prepared in a nuclear reactor can be used to both _____________ and
________________ various medical conditions. Tracers can be used to _____________
a particular isotope through its normal path in the body to show any _________________.
Tracers used in the body will typically have _____________ half-lives.
o Iodine-123 is used to study ___________________________ function.
o Technetium-99 is used to locate _________________ and can also collect in
_________________.
o Barium-140 is used in upper and lower GI studies to find ____________________
and _______________________________ problems.
o Thallium-201 collects in ________________muscle.
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
Diagnostic Equipment
o Computer-Axial Tomography scans or ______________ scans use
_____________________ to produce cross-sectional images of the body.
o Magnetic Resonance Imaging or ___________ uses ______________________
to “see through” bones to produce images of soft tissue.
o Positron Emission Tomography or _______________ scans use a
_____________________________ attached to a sugar molecule to detect and
display differences between normal and cancerous tissue.

Cancer Treatment using radiation
o ___________________ and ________________ are used to treat shallow tumors.
o ___________________ is used to treat thyroid cancer.
o ___________________ is used to treat leukemia.
o
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Exposure to Radiation:
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D. Measurement of Radioactivity
1. Units

rad measures the absorbed _____________ of radiation.

rem measures the _______________________________ effect on living organisms.
o In humans, ionizing radiation is measured in millirem, abbreviated ___________.

The maximum annual dose is _______________ mrem.

The average annual dose is _______________ mrem.
2. Devices used to measure radioactivity:
In the Laboratory
In the Workplace
1.
2.
3.
E. Half-Life is the time for ________________ of the nuclei in a radioactive sample to decay.
1. Abbreviation: ____________
2. Units can vary from ___________________ to ___________________ of years.
3. Example: Plutonium-239 has a half-life of 24,000 years. A sample of this plutonium today
will be half gone in _____________________. A 16-g sample today will have a mass of
_______________ in 24,000 years. After another 24,000 years, its mass will only be
______________.
4. Problems
a. A radioactive element has a half-life of 64 years. You have a 48-g sample of this
element. What is its mass in 192 years? (amount problem - How much)
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b. Another radioactive sample has a half-life of 37.2 minutes. How long will it take for a
55-g sample to decay to 3.4 g? (time problem - How long or how old)
c. The half-life for fluorine-18 is 109.8 minutes. How long will it take a 3.60 μg sample to
decay to 0.225 μg?
d. The half-life for americium-241 is 432 years. How much of a 50 mg sample will remain
after 1296 years?
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II. Nuclear Energy
A. Sources
1. Nuclear Fission is the _______________________ of a large nucleus into smaller nuclei
of similar size.
93
1
U  01n  140
56 Ba  36 Kr  3 0 n  energy
235
92

A ____________ amount of mass is converted into a ______________ amount of energy

Examples
o Atomic bomb uses U-235 or plutonium.
1st military use of an atomic bomb was in ______________________________ on
August 6, 1945 during World War II.
o Nuclear Power Plants

A ________________________________ occurs when the material used to start the
reaction is also produced until the fuel is used up.
o In the above fission reaction, the fuel is ______________________ and the starter
for the reaction is the ______________________.

____________________ _______________ is the minimum amount of fissionable
material present (the fuel) to sustain a chain reaction.
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2. Nuclear Fusion is the ___________________________ of smaller nuclei to form a larger
nucleus.
2 1H + 2 2H
1

→
1
4
He + 2 1H + energy
2
1
A _____________________ amount of mass is converted into a
_____________________ amount of energy that is 4 to 7 times more than a fission
reaction.

Examples
o Sun
o Hydrogen bomb

We are currently unable to control fusion as an energy source.

Temperatures of ___________________________are required.

Fusion produces ________________________ waste.
B. Nuclear Power Plants
1. Commercial Use

1st plant in US________________________________________________________

1st plant in the world __________________________________________________

In the US, there are ____________ units in ___________ states to generate
__________ of our electricity.

There are __________ plants in Pennsylvania.

__________________________________________ is the closest nuclear plant to NPHS.

Worldwide, there are ______________ plants in over 30 countries that provide
__________ of the world’s electricity. In France, __________ of its electricity is
produced by nuclear energy.
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2. Overall process at a nuclear power plant:
fission reaction → produces heat → to heat water into steam (545oC) →
the steam drives turbines in a generator → the generator produces electricity
3. The chain reaction of a fission reaction takes place in a nuclear reactor.

The reactor is made up of a fuel, control rods, a moderator, and a coolant.

Nuclear reactors are housed within a concrete containment structure.
4. The fuel is U-235.

Nonfissionable uranium is ________________.

Uranium ore contains 0.7% U-235.

The enriched fuel is packed as ____________________ of 3% U-235 and 97% U-238

Weapons-grade uranium is at least 90% U-235.

The pellets are packed into long steel cylinders called _________________________
that are 12-14 feet in length.

Fuel rods are replaced every ________ months.

Used fuel rods are known as _______________ fuel rods.
5. Control rods are used to absorb the _________________ resulting in slowing down or
stopping the chain reaction.

_________________ and ____________________ are commonly used in control rods.
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6. A Moderator is used to _____________________________the high-speed neutrons for
more fission reactions to occur.

Common materials used as moderators are ___________________________________,
_________________________________________, or __________________________ .

Heavy water is D2O, where D is _________________________________.

Light water is _________________________________________ or H2O.
7. A Cooling system is used to cool the _______________________.

Water outside of the reactor is used to cool the steam.

The cooled steam _____________________________ into water and is reused inside the
reactor.

The water used to cool the steam is cooled itself through a _________________________
before it is discharged to a receiving body of water, such as, a river.

Water in the cooling tower __________________________ come in contact with the
reactor core.

Each nuclear reactor has a cooling tower.

At the Limerick Generating Plant, the primary water for the cooling system comes from
the _________________________________ River and its secondary source is from the
______________________________ River.

At the Limerick Generating Plant, the cooled water is discharge into the
_________________________________ River.
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C. Advantages and Disadvantages of Nuclear power Plants
1.
Advantages
Disadvantages
1.
1.
2.
2.
3.
3.
4.
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2. Nuclear Waste
a. Types

High-level nuclear waste is radioactive waste products with _______________
levels of radioactivity.

Low-level nuclear waste is radioactive waste products with _______________
levels of radioactivity.
b. Sources

High-level nuclear waste
o _______________________________________________________
o _______________________________________________________

Low-level nuclear waste
o ________________________________________________________
o ________________________________________________________
o ________________________________________________________
e. Other Facts

Spent fuel rods are still highly radioactive for _____________________________ of
years.

About 3100 ________________ of commercial high-level nuclear waste are produced
annually in the US.

There is no permanent storage place for high-level nuclear waste in the US.

Federal law mandates the spent fuel rods are stored _________________________,
usually in steel-lined storage tanks or pools of water.

Some plants are keeping the spent fuel rods in dry cask concrete vaults on the surface.

US government is developing a permanent storage site in
________________________________________ in Nevada.
o The waste will be buried at least ___________________ below the surface in
vaults.
o Progress for completion has been delayed from 1998 to 2017 at the earliest.
o Delays are due to ____________________,
___________________________________, and
____________________________________ concerns.
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D. Nuclear Accidents
1. Three-Mile Island

Date: _______________________________

Location: ________________________________________________________________

______________________________________ and ______________________________
lead to the worst nuclear accident in US.
2. Chernobyl

Date: _______________________________

Location: ________________________________________________________________

_______________________________________________ and
_______________________________________________ resulted in the worst nuclear
accident in the world.
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