• Specifying decays and half-lives
• Renaming components of the model

• The Decay dialogue sets up the parent-daughter pairs and the decay constants that define their relationship
• Half-lives define the length of time taken for the radioactivity of a contaminant to fall to half of its original value. The half-life of a contaminant is inversely proportional to its decay constant.

This video covers section 5.3 of the User Guide.