What is Electron-volt and atomic mass unit?

Two units tailored to the nucleus. The electron-volt, the energy an electron gains crossing $1\,\mathrm{V}$ (Chapter 12): $1\,\mathrm{eV} = 1.60 \times 10^{-19}\,\mathrm{J}$, $1\,\mathrm{MeV} = 1.60 \times 10^{-13}\,\mathrm{J}$ — chemical bonds trade a few $\mathrm{eV}$, nuclear reactions megaelectron-volts. The unified atomic mass unit, one twelfth of the mass of a carbon-12 atom: $1\,\mathrm{u} = 1.660\,54 \times 10^{-27}\,\mathrm{kg}$, of energy equivalent $931.5\,\mathrm{MeV}$ — $1\,\mathrm{u} = 931.5\,\mathrm{MeV}/c^2$.