Radioactivity has the dimension length squared mass per time. The SI composite unit of radioactivity is the kilogram meter squared per second.

Maple knows the units of radioactivity listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, becquerel[SI] or Ci[radiation]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, becquerel or Ci.

The units of radioactivity are defined as follows.

A becquerel is defined as a radionuclide decay per second.

A curie is defined as  radionuclide decays per second.

A rutherford is defined as  radionuclide decays per second.