1. Chapter 25
Nuclear Radiation

2. Section 25.1
Nuclear Radiation

3. Characteristics of Chemical and Nuclear Reactions
Chemical Reactions
Occur when bonds are broken or formed
Atoms remain unchanged, though they may be rearranged
Involve only valence electrons
Associated with small energy changes
Reaction rate is influenced by temperature, pressure, concentration and catalysts
Nuclear Reactions
Occur when nuclei emit particles and/or rays
Atoms are often converted into atoms of another element
May involve protons, neutrons, and electrons
Associated with large energy changes
Reaction rate is not normally affected by temperature, pressure, or catalysts

4. Discovery of Radiation
Wilhelm Roentgen – discovered what he called X rays
Henri Becquerel – determined that phosphorescent minerals would emit X rays spontaneously
Marie and Pierre Curie – isolated the components emitting the X rays from a mineral sample. Pioneers of the nuclear chemistry field of science. Identified polonium and radium as elements

5. Types of Radiation
Radioisotopes are the isotopes of atoms with unstable nuclei that will emit radiation to become more stable
There are three common types of radiation

6. Properties of Alpha, Beta, and Gamma Radiation
Property
Alpha (α)
Beta (β)
Gamma (γ)
Composition
Alpha particles
Beta particles
High-energy electromagnetic radiation
Description of Radiation
Helium nuclei
Electrons
Photons
Charge 2+ 1-
Mass
6.64x10-24 kg
9.11x10-28 kg
Approximate energy
5MeV
0.05 to 1 MeV
1MeV
Relative penetrating power
Blocked by paper
Blocked by metal foil
Not completely blocked by lead or concrete