The "Mass Defect", also termed mass deficit, or mass packing fraction, describes mass change (decrease) in bound systems, particularly atomic nuclei.
Applicable units are those of quantitykind:Mass
http://en.wikipedia.org/wiki/Binding_energy
The "Mass Defect", also termed mass deficit, or mass packing fraction, describes mass change (decrease) in bound systems, particularly atomic nuclei.
$B = Zm(^{1}\textrm{H}) + Nm_n - m_a$, where $Z$ is the proton number of the atom, $m(^{1}\textrm{H})$ is atomic mass of $^{1}\textrm{H}$, $N$ is the neutron number, $m_n$ is the rest mass of the neutron, and $m_a$ is the rest mass of the atom.
http://www.iso.org/iso/catalogue_detail?csnumber=31895