Physics answers half life and radioactive dating
Radioactive isotopes, or radioisotopes, carbon 14 dating worksheet half life and ...
= tau*ln(2), where tau is a property called the "mean lifetime" of the substance and has units of years.
It relates the lifetime of an alpha emitter to the energy released in the decay using the approximately-valid assumption that nuclear density is constant and that the nucleus has a relatively sharp edge.
For beta decays there is quantity "$ft$" which convolves the half-life of the decay with the electrical interaction between the emitted electron and the positively-charged daughter nucleus.
Answering this question is one of the major successes of 20th-century physics.