Nuclear
Chemistry
• Nuclear chemistry is the study of the
structure of atomic nuclei and the
changes they undergo.
• Isotopes of atoms with unstable nuclei are
called radioisotopes.
• Unstable nuclei emit radiation to attain
more stable atomic configurations in a
process called radioactive decay.
• During radioactive decay, unstable atoms
lose energy by emitting one of several
types of radiation.
• Elements with atomic # higher than 83 are
all radioactive.
Types of Radiation
1. Alpha particles 
• Given off when a nucleus releases 2
protons and 2 neutrons
• Same as a helium nucleus
• Largest and slowest form of radiation
• Least penetrating
• Can be stopped by a sheet of paper
Alpha Decay
Beta particles 
2.
•
Neutron decays into a proton and electron
•
Electron (beta particle) is emitted at very
high speed
•
Proton stays in nucleus
•
Increases the atomic number by one – new
element is formed
•
Does not affect the mass number
•
Much faster than alpha particles
•
Can be stopped by a thin metal foil or wood
Beta decay
3. Gamma rays 
• Most penetrating and potentially
dangerous
• Highest energy and frequency
• No mass, no charge
• Travel at speed of light
• Lead and concrete used to stop rays
Which type of radiation would be
detected at sites 1, 2, & 3 below?
Half-Life
Amount of time it takes for half of a
sample of radioactive isotope to decay
Carbon-14 is used in radioactive dating
 Half-life of carbon is 5730 years.

Calculating Amount of Remaining Isotope
• Iron-59 is used in medicine to diagnose blood
circulation disorders.
• The half-life of iron-59 is 44.5 days.
• How much of a 2.000-mg sample will remain
after 133.5 days?
Honors Half-Life Problems Answers
1. 0.125 mg
2. 2016
3. 25 mg
4. 1 mg
5. 0.625 mg
6. 6.0 years
75 min
8. 31,250 atoms
9. 0.0625 g; 102.4 g
10. 20 minutes
1
18
11. 3.875 x 10 atoms, 32
12. 120 s
7.
1
32
Detecting Radiation
Devices:
1. Geiger
counter
2. Film
badge
Uses of Nuclear Energy &
Radiation
Radioactive dating
uses isotopes of known
half-life to determine
age of rocks, fossils,
etc.
Cancer therapy
(radiation treatment)
gamma radiation kills
cancerous AND healthy
cells
Imaging
inject radioactive isotopes
into the body
“see” the inner workings of
the body by following
radioactive isotopes
Smoke detectors
Nuclear Fission
splitting of a nucleus into smaller
fragments
releases tremendous amount of E
atomic bombs =
uncontrolled fission
reactions
nuclear reactors =
controlled fission
reactions

heat used to generate
steam & electrical
power
Da Bomb
Effects of the Atomic Bomb
Nuclear Fusion
Also called thermonuclear reactions
Combining of two or more nuclei to form
one nucleus of larger mass
Requires extremely high temperatures
or strong magnetic field
Occurs in the sun & H-bombs
2
1
3
1
H
H
1
0
n
4
2
He