Nuclear Energy Notes
Name _______________________________
18.2 & 18.3
Period _________ Date_________________
1. Nuclear Reactions: Change the composition of an atom’s ____________________.
2. The __________________ __________________ ________________ holds the nucleus together.
3. Most atoms are ________________ (equal number of _____ & _____). These are the
____________________ atoms which are NOT ________________________.
4. ________________ nuclei have more ____________________ than protons. These isotopes are
_____________________.
5. As the elements become __________________they become more unstable.
6. All elements have at least ______ radioactive isotope. All the isotopes of those elements with
atomic numbers greater than _______ are radioactive.
7. The larger nuclei are radioactive because they have more ___________________ than protons.
8. Characteristics of Subatomic Particles and Rays:
Particle
Mass (amu)
Proton
1.00727647
Neutron
1.00866490
Beta Particle
(electron)
Alpha Particle
(He nucleus)
Gamma ray
0.000548580
Charge
Symbol
Stopped by
4.00150617
0
1
9. Spontaneous Emission of Radiation:
A. Unstable nuclei will ___________________________ emit 3 types of natural radiation, this is
also called radioactive _________________.
B. When an atom emits 1 kind of ____________________ the original nucleus _______________
or decays to form a ___________ nucleus and releases ____________________. This is
written in a ______________________ _______________________.
10. 3 Types of Spontaneous Radiation:
A. Alpha Decay – spontaneous emission of alpha particle from the nucleus.
226
88
Ra  222
86 Rn  ____
185
79
Au  _________  42 α
B. Beta Decay – spontaneous emission of beta particle from the nucleus
14
6
C  ________  01β
131
53 I
 ________  01β
C. Gamma Decay – spontaneous emission of gamma ray from the nucleus
238
92
U  ________  00 γ
11. Transmutation: Changing into a __________ element by either decay or bombardment.
Nuclear Bombardment Reactions:
A. Process in which a new ____________________ is formed by _______________________
a nucleus with small energetic particles.
B. The energetic particle, a _______________, hits the _________________ nucleus and forms
C. an unstable ___________________ _________________, which is short-lived.
D. This nucleus can emit an ___________________ ___________________ to stabilize itself.
E. This is the process used in ___________________ ___________________ where
artificial isotopes and ___________________________ (those above U) elements have been
produced.
Ex.)
14
7
N  24 He  [ 189 F]  178 O  11 H
Unstable
Compound Nucleus
2
12. Nuclear Fission:
A. Process by which a heavy nucleus _____________ into two smaller nuclei
B. Most fission reactions are _____________________.
C. The energy yield for fission reactions are very _________________.
D. Fission reactions are the source of energy used to generate electricity in __________________
_________________ __________________.
E. __________________ & ____________________ are the radioisotopes used in reactors.
235
92
93
140
1
U  01 n  [ 236
92 U]  36 Kr  56 Ba  3 0 n
Temporary
Nuclei
F. In fission reactions, the product nuclei have far too many __________________, and are
intensely radioactive. This is considered _______________________ _______________.
G. The ___________________ ________________ can cause another reaction as long as
sufficient U-235 remains.
H. This is called a ________________ _____________________.
I. The smallest amount (minimum volume) of fissionable material needed to sustain a chain
reaction is called the ___________________ ____________.
3
13. Nuclear Reactors:
A. There are currently __________ commercial nuclear power plants in the U.S. They provide
________ of our country’s electricity, but ________ of the electricity used in southeastern PA.
B. There are _________ nuclear reactors in 30 nations around the world that provide ________ of
the world’s electricity. To produce electricity you need to turn a turbine. This can be
accomplished by wind or water, must most commonly by ________________. The only
difference between a nuclear power plant and a conventional fossil fuel plant is the method
used to produce _____________ __________.
14. Parts of a Nuclear Reactor
A. Fuel Rods: Composed of 97% U-238 and 3% _____________ (the fissionable isotope).
______________ - sized pellets are arranged in long steel cylinders in the reactor _________.
When the fuel has given up most of its energy it is called _____________. It will be reloaded
every 1 to 3 ___________. There can be 10,000,000 pellets in 1 plant.
B. Control Rods control the ______________ of a nuclear reaction. Without them the reaction
would occur too ______________ for it to be effective.
C. Moderator is usually _______________ water (D2O). Without sufficient cooling of the
core a ________________________ could occur. This water also shields workers.
D. Generator produces electricity by turning a steam _________________ from the boiling water.
4
E. Cooling System: Water from outside is used to cool the steam (it does not come into contact
with the cooling water in the core). Excess _______________ rises up in the cooling tower,
condenses and falls back.
* Cooling Towers are not shown in this picture.
15. Radioactive Waste:
A. _____________ fuel rods have been accumulating for about 40 years. Spent fuel rods are highly
radioactive, with some isotopes remaining active for ____________________ of years. By federal
law reactor waste must be _____________ on site. The U.S. Government has not yet opened any
permanent storage sites, but one called ___________________________ in Nevada is currently
being negotiated. On-site storage is only a _________________ measure, as tanks require too much
maintenance to be safe for _____________ term storage.
16. Nuclear Fusion:
A. This is a thermonuclear reaction - requires __________ temperatures.
B. Occurs when two small nuclei _____________, or ___________, to form larger, more stable
nuclei.
C. Releases a _____________ amount of energy.
D. Process that occurs on the __________ and in a ___________________________________.
5
E. If fusion reactions are going to be practical, they need to produce more __________________
than they require to get started.
F. In a fusion reaction, the starting materials are in a form of _____________________.
G. The biggest problem is obtaining the high ____________________ necessary for a fusion
reaction to occur.
2 21 H  2 11 H  24 He  2 11 H  ENERGY
H. A “__________________ ______________” could be used to hold the plasma at these high
temperatures.
17. Uses for Nuclear Chemistry:
A. Half life
1. The time required for ______________________ of a radioactive isotope to decay.
2. Using radioactive isotopes to determine the age of an object is called:
_______________________________.
Ex. If I have 1.00 mg of
After 2? After 3?
131
53
I , (½ life = 8.04 days) how much will be left after 1 half-life?
B. Radioactive Isotopes and Dating
1. All animals and plants contain _____________________.
2. Even though carbon-14 undergoes ______________________________, it is constantly
replenished during a lifespan.
3. The half-life of carbon-14 is __________________.
4. The ratio of __________________ to _________________ is compared to another
object of a similar age.
5. Cannot use carbon-14 dating with objects____________________________________.
6. After 4 half lives, the amount of carbon-14 remaining is too ______________ to give
reliable data.
7. Carbon-14 is not useful for specimens over _____________ years old, so Potassium-40
is used instead. It has a half-life of 1.28 billion years.
6
C. Smoke Detectors:
1. Smoke detectors emit a small amount of ____________________________.
2. When smoke particles mix with the gas, they __________ the current flow setting off
the alarm.
D. Medical Uses:
1. CAT SCAN – the body is analyzed using ___________________.
2. MRI and NMR – detects body’s absorption of _____________________________.
3. PET – Measures ____________________ from certain part of the brain.
4. 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 abnormalities.
Ex) Upper and Lower GI uses radioactive _________ to detect stomach and intestinal
problems. An IVP measures the bodies absorption of radioactive iodine to detect
_________________ _______________.
5. Irradiation can be used as an energy source to _________________ cancer. The
diseased area is _______________________ to ionizing radiation to kill cancerous cells.
Ex) Ingest large amounts of I-131 kills thyroid cancer, External beam of C0-60 can be
directed at a cancerous spot. Irradiation can also be used to ____________________
medical instruments and ___________________ food.
18. Exposure to Radioactivity:
A. _________________ exposure to radiation is dangerous; therefore, people working in these
conditions must monitor their exposure to radiation.
B. People working with radiation wear ____________________________ to monitor their
exposure.
C. A ________________________ measures radiation in people, a _________________
________________ measures radiation of objects.
D. Radiation is usually measured in units of ___________. Higher doses for a longer period of
time over a large area cause the most damage, especially for rapidly dividing cells like
________ cells and ___________ cells.
7