Nuclear
Chemistry
"in recognition of the extraordinary services he has
rendered by his discovery of spontaneous radioactivity”
Nobel Prize in Physics 1903
Henri Becquerel
Pierre Curie
Marie Curie
What causes radiation or nuclear
decay?
The
presence of too few or
too many neutrons
compared to protons leads
to an unstable nucleus.
Reminder
Mass number=Protons + Neutrons
15
7
Atomic number=Protons
N
Radioisotopes
Radioisotopes
Isotopes that have an
unstable nucleus
Nuclear Reactions and Radiation.

Nuclear Reactions: Reactions in which

Radiation : These changes are accompanied

Transmutation: the conversion of one
radioisotopes gain stability by undergoing
changes.
by the release of large amounts of energy.
chemical element or isotope into another
through nuclear reaction.
Radioisotope
Nuclear Reaction
Radiation
Radioactive Decay
 Radioactive
Decay - The
process where an unstable
nucleus loses energy by
emitting particles of radiation.
Alpha Decay


Consists of a helium nuclei that has
been emitted from a radioactive
source.
4
Symbol:
 Example:

230
90
Th
He
2
226
88
Ra
4
2
He

Beta Decay
A
neutron is converted to a proton
and an electron. The electron is
emitted, the proton stays.
0
 Particle Emitted:
1
 Symbol:
 Example:
e

14
6
C
14
7
N
0
1
e
Gamma Radiation

Gamma radiation is emitted often
times along with alpha and beta
radiation. It has no mass or electrical
charge. It is high energy radiation
and is very dangerous!
 Particle:



Symbol:
Radioactive particles
Penetrating
power:
Summary
Property
Alpha
Radiation
Beta
Radiation
Gamma Radiation
Composition
(Helium
Nucleus)
Electron
High energy
electromagnetic
radiation
Symbol
4
2
He
0
1
e
γ
Charge
2+
1-
0
Mass
4
1/1837
0
Radium-226
Carbon-14
Cobalt-60
Low
Moderate
Very high
Paper,
clothing
Metal foil
Lead, concrete
Common Source
Penetrating
Power
Shielding
Complete page 18 for Homework
Radioactivity and Radioactive Decay

1.
2.
Today’s Objective
Write nuclear decay equations to depict the nuclear decay of
radioisotopes.
Predict the type of nuclear decay using the band of stability.
How do we write nuclear equations?

A nuclear equation will look like this:
1. Isotope  particle + element

Because of the law of conservation of mass, all mass numbers and
atomic numbers, or the tops and bottoms of the complete
symbols, must balance on either side of the arrow.
2. When you write your equation, balance your
mass numbers followed by your atomic numbers.
Writing Nuclear Decay Equations
Nuclear Equations: Practice
1.
2.
3.
C   C
14
6
0
0
14
6
Word Equations
4. Write the
equation of lead-210 undergoing alpha decay.
5. Write the equation where lead-210 emits a beta particle.
6. Show the transmutation of uranium-237 as it undergoes
alpha decay. What is the nuclide that is produced?
Homework: page 20
Transmutation
•
•
The process where a nucleus becomes a
NEW nucleus because the number of
protons has been changed.
What is the only type of radiation that does
NOT change the atomic number?
 Gamma (λ)- it has 0 mass and 0 charge,
therefore does not affect the nucleus size!

Fission and Fusion


Show “Nuclear Power and Its
Effect on the World”
http://www.youtube.com/watch?v=ur6Kb62Ci5k
Fission and Fusion
Fission
Fusion
Bombard nuclei with neutrons
Atom falls apart
Lots of energy evolved
Can create a chain reaction
Instantaneous
Ex:Atomic Bombs, nuclear reactors
Requires input of energy
Two nuclei combine to make new
atom of Helium
Releases more energy than fission
Difficult to control
Ex: Sun uses fusion
Fission Reaction/ Chain Reaction
FUSION
Nuclear Power

In the News!!!!!

60 Minutes Report Fukushima Nuclear Power Plant
Japan
http://www.youtube.com/watch?v=z6cYE7PwMik