Transcript Nuclear Decay Powerpoint

Nuclear Decay
B5
Radioactive Decay

When the nucleus of an atom breaks
down to form a different element
Nuclear decay
Is a form of Ionizing radiation
 Emitted particles – particles given off by
the nucleus of atom
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
As a result the nucleus
of the atom is changed
into a new atom
Ernest Rutherford

He found that there were 3 types of
radiation / decay
Alpha
 Beta
 Gamma

Decay type: charge and Greek
symbol
Radiation
Type
Alpha
Beta
Gamma
Charge
Greek
Symbol
Alpha Radiation

made of two protons and two neutrons
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Low energy and large molecule

Penetrating power: Stopped by paper

Inside the body however: very powerful
tissue-damaging agents
Beta radiation
Made of an electron
 0-1e
 High energy, very small (negligible
mass)
 Penetrating power: Stopped by
aluminum

Gamma radiation

Made of Pure Energy
0
γ
0
Extremely high energy
most dangerous radiation
 Penetrating power: Stopped by several
centimeters of lead or concrete
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Penetrating powers
Review:
Atomic number (Z)=number of protons in nucleus
Mass number (A)=number of protons + number of neutrons
= atomic number (Z) + number of neutrons
Mass Number
Atomic Number
A
ZX
Element Symbol
Balancing a nuclear decay
reaction
Key to balancing nuclear equations is…
both atomic numbers and mass numbers
are conserved!
 Reactant Side Product Side
Sum of Mass # = Sum of Mass #
Sum of Atomic # = Sum of Atomic #

Practice
Compound undergoes alpha and gamma decay
239Pu
94
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Compound undergoes beta decay
235U
92
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