Question

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

Answer 1

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`