Chapter 22

1
Chapter 22 Nuclear Chemistry
2
Nuclear Symbols
Mass number (p no)
Element symbol
Atomic number (number of p)
3
Types of Radioactive Decay
4
2

• alpha production (a) helium nucleus
• beta production (b)

He
2
0
e
-
1
4
Alpha Radiation
Limited to VERY large nucleii.
5
Beta Radiation
Converts a neutron into a proton.
6
Types of Radioactive Decay

• gamma ray production (g)
• positron production
• electron capture (inner-orbital electron is
  captured by the nucleus)

0
e
1
7
Types of Radiation
8
Deflection of Decay Particles
attract
Opposite charges_________ each other.
repel
Like charges_________ each other.
9
NuclearStability
Decay will occur in such a way as to return a
nucleus to the band (line) of stability.
10
Half-life Concept
11
Sample Half-Lives
12
A Decay Series
A radioactive nucleus reaches a stable state by a
series of steps
13
Nuclear Fission and Fusion

• Fusion Combining two light nuclei to form a
  heavier, more stable nucleus.
• Fission Splitting a heavy nucleus into two
  nuclei with smaller mass numbers.

14
Energy and Mass

• Nuclear changes occur with small but measurable
  losses of mass. The lost mass is called the mass
  defect, and is converted to energy according to
  Einsteins equation
• DE Dmc2
• Dm mass defect
• DE change in energy
• c speed of light

Because c2 is so large, even small amounts of
mass are converted to enormous amount of energy.
15
Fission
16
Fission Processes
A self-sustaining fission process is called a
chain reaction.
17
A Fission Reactor
18
Fusion