Question

Which quantity can be calculated using the equation E = mc2?
the energy needed to split an atom into separate protons, neutrons, and electrons
the energy needed to split the nucleus into separate protons and neutrons
the energy needed to remove an electron from an atom
the energy needed to add an electron to an atom

Answer 1

the energy needed to split the nucleus into separate protons and neutrons

Explanation: E = mc² gives the energy equivalent of a mass change. In nuclear reactions the "mass defect" (mass of separated nucleons minus mass of nucleus) times c² equals the nuclear binding energy — the energy required to split the nucleus. Ionization energies (remove/add an electron) are electromagnetic binding energies, not normally calculated from E = mc².