ISCI 2002 Chapter 13

Radioactivity

Unstable atomic nuclei

Most radiation we encounter is:

Three Components of Radiation from Radionuclides

Types of radiation:

Alpha particle:

Beta particle:

Gamma rays:

Common Particles Encountered in Nuclear Reactions

alpha particle=

In a nuclear decay equation, the sums of the mass numbers (A) and the sums of the atomic numbers (Z) will be equivalent on each side

when an atom undergoes radioactive decay, it

The atomic nucleus and the strong number force

the strong force is only between close together nucleons. For far apart protons, the electric force is greater

Half-Life:

Half-Life:

Decay of Thorium234 over two half-lives Thorium234 has a half-life of 24 days.

Finding the Elapsed Time