Find the binding energy of , whose atomic mass is 12.019 u?

1 Answer
May 4, 2018

81 MeV

Explanation:

Nitrogen 12 consists of 7 protons (because it is nitrogen) and 5 neutrons (because 12 total nucleons - 7 protons = 5 neutrons). We can look up the masses of each of these individually:

#m_p = 1.0073\ u and m_n = 1.0087\ u #

So adding these up:
#7m_p + 5m_n = 7 * 1.0073 \ u+ 5 * 1.0087\ u = 12.095\ u #

Therefore the change in mass is
#Delta m = (12.095\ u - 12.019\ u) = 0.087\, u #

The equivalent energy is
#E = mc^2 = 81\ MeV #