Decay constant

The quantity decay constant (commonly denoted by the Greek letter λ) is the fraction of the activity that decays per unit of time (t). The corresponding unit is per second (in s^-1).

The quantity half-life (t_½) is the period of time (in s) after which the activity is reduced to half the original value. The relation between half-life and decay constant is:

t_½ = ln(2) / λ

Related concepts

• activity
• atom
• electromagnetic radiation
• electron
• half-life
• molecule
• neutrino
• neutron
• nuclear decay
• positron
• proton
• X-radiation