Nuclear Chemistry:
Types of Nuclear Radiation
Unstable Atoms
 Unstable atoms emit excess energy from their
nuclei to become more stable. The energy and
particles released are called nuclear radiation.
+
Unstable
Nucleus
Stable
Nucleus
+
Particles
Energy
Radiation
Types of Radiation
Alpha Particles:
Identical to a helium nuclei.
Beta Particles:
Electrons emitted as radiation.
γ
Gamma Rays:
Emitted as a wave, not a particle.
4
2 He
0
-1
e
0
0
γ
Alpha Particles
 Alpha particles are identical to helium
nuclei..
 Because they are large, they the least
penetrating power. Can be stopped by paper
or skin.
 Least dangerous form of radiation.
4
2
He
Beta Particles
 Beta Particles are electrons that are
emitted from nuclear radiation.
 Because they are much smaller, beta
particles travel faster and can penetrate
clothing and skin..
 Can be stopped by metal or wood
 Has No mass.
Gamma Rays
γ
 Gamma particles are emitted in the
form of waves.
 They have No mass which gives them a
high penetrating power.
 Extremely dangerous. Can be stopped
by thick layers of concrete or lead.
Strength of Radiation
? Radiation
? Radiation
? Rays
Sheet of
Paper
Sheet of
Aluminum
Thick
Concrete Wall
Strength of Radiation
Alpha Radiation
Beta Radiation
Gamma Rays
Sheet of
Paper
Sheet of
Aluminum
Thick
Concrete Wall
Alpha Decay
238
92
U
Unstable
Nucleus
234
90
Th + He
Stable
Nucleus
4
2
Alpha
Particle
Alpha Decay
238
92
U
234
90
Th + He
4
2
An unstable atom spits out an alpha particle )helium
atom).
Notice the mass on both sides of the reaction remains the
same.
Beta Decay
14
6
C
Unstable
Nucleus
14
7
N + e
Stable
Nucleus
0
-1
Beta
Particle
Beta Decay
14
6
C
14
7
N + e
0
-1
A neutron turns into a proton and emits an electron.
Notice the mass on both sides of the reaction remains the
same.
Gamma Decay
99
43
Tc*
Unstable
Nucleus
99
43
Tc + γ
Stable
Nucleus
0
0
Gamma Ray
Gamma Decay
99
43
Tc*
99
43
Tc + γ
0
0
An unstable atom emits pure energy in the form of
gamma radiation. Gamma radiation has no mass, so the
atom remains unchanged.
Notice the mass on both sides of the reaction remains the
same.
Writing Nuclear Reactions
An unstable atom emits pure energy in the form of
gamma radiation. Gamma radiation has no mass, so the
atom remains unchanged.
Notice the mass on both sides of the reaction remains the
same.
Uses of Radiation
 Cancer Treatment:
Radiation is used to destroy cancer cells.
 Nuclear Medicine:
Radioactive substances can be inserted into
the body to view internal organs.
 Food Irradiation:
Radiation can be used to reduce
or eliminate bacteria on food.