Formula: Mass Defect Mass of the nucleus Neutron number Proton number
$$\class{brown}{\Delta m} ~=~ Z \, \class{brown}{m_{\text p}} ~+~ N \, \class{brown}{m_{\text n}} ~-~ \class{brown}{m}$$
$$\class{brown}{\Delta m} ~=~ Z \, \class{brown}{m_{\text p}} ~+~ N \, \class{brown}{m_{\text n}} ~-~ \class{brown}{m}$$
$$\class{brown}{m} ~=~ Z \, \class{brown}{m_{\text p}} ~+~ N \, \class{brown}{m_{\text n}} ~-~ \class{brown}{\Delta m}$$
$$N ~=~ \frac{ \class{brown}{\Delta m} ~+~ \class{brown}{m} ~-~ Z \, \class{brown}{m_{\text p}} }{ \class{brown}{m_{\text n}} }$$
$$Z ~=~ \frac{ \class{brown}{\Delta m} ~+~ \class{brown}{m} ~-~ N \, \class{brown}{m_{\text n}} }{ \class{brown}{m_{\text p}} }$$
Mass difference
$$ \class{brown}{\Delta m} $$ Unit $$ \mathrm{kg} $$
The mass difference \(\class{brown}{\delta m}\) of the individual nuclei components and the mass \(\class{brown}{m}\) of the nucleus is not zero. This is called mass defect. This mass difference hides in the binding energy of the nucleus.
Mass of the nucleus
$$ \class{brown}{m} $$ Unit $$ \mathrm{kg} $$
Mass of the nucleus formed by the union of \(N\) neutrons and \(Z\) protons. The nucleus is lighter than the sum of its components (mass defect).
Neutron number
$$ N $$ Unit $$ - $$
Number of neutrons used to build a nucleus.
Proton number
$$ Z $$ Unit $$ - $$
Proton number (atomic number) is the number of protons used to build a nucleus.
Mass of a neutron
$$ \class{brown}{m_{\text n}} $$ Unit $$ \mathrm{kg} $$
The rest mass of a neutron is:
$$ \class{brown}{m_{\text n}} ~=~ 1.674 \cdot 10^{−27} \, \mathrm{kg} $$
Mass of a proton
$$ \class{brown}{m_{\text p}} $$ Unit $$ \mathrm{kg} $$
The rest mass of a proton is:
$$ \class{brown}{m_{\text p}} ~=~ 1.672 \cdot 10^{−27} \, \mathrm{kg} $$