Radioactive Decay
Radioactive
Decay
Radioactive Decay:
• Some unstable atoms try to regain stability by
losing energy. They lose energy by emitting
radiation.
• These elements continue to undergo radioactive
decay until they are stable
Radioisotopes: Types of isotopes are capable of
radioactive decay
Stable versus Unstable
• Stable:  not likely to decay
• Unstable:  will decay eventually
• Different Isotopes have different degrees of
stability
Eg. Carbon-12 = Stable
Carbon-13 = Stable
Carbon-14 = Unstable
All three are found in the human body
Three Types of Radiation
Alpha Radiation: A stream of alpha particles
Alpha Particles: positively charged atomic
particles. The largest of the three types
What is it made of: The alpha particle is made
of the same particles as a helium atom (2
protons, 2 neutrons)
Equations for alpha decay
Equations where atoms lose alpha
particles
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Three Types of Radiation
Beta Radiation: Caused by the flow of beta
particles
Beta Particle: an electron
During Beta Decay: A neutron becomes a
proton and an electron. This proton stays in
the nucleus while the electron leaves
Equations for beta decay
• p
Equations for beta decay
• p
Three Types of Radiation
Gamma Radiation: Rays of high energy, short
wavelength radiation. Has almost no charge
and no mass.
Gamma Decay: The redistribution of energy
within the nucleus.
Equations for gamma decay
Equations for gamma decay