please answer question [A], [B], and [C]

Matrix Hartree-Fock orbital energies of the F atom (Z=9) were found to be (in atomic units): [A] Use the Koopmans' Theorem to obtain an estimate (in eV) of: (a) the smallest ionization energy of the F atom (b) the largest ionization energy of the F atom (c) the electron affinity of the F atom [B] Which of the calculated quantitics, (a), (b), or (c) is the most accurate and why? You may find experimental ionization energies at the NIST Atomic Spectra Database Ionization Energies Form You may find the electron affinity of fluorine at Search for Species Data by Chemical Formula (NIST Chemistry Webbook: Enter the atomic symbol F as the desired chemical formula and select Ion energetics box). [C] State what is the total Hartree-Fock energy (in atomic units) of the F atom with electronic configuration 1s22s22p5, if the only data that you have are the occupied orbital energies of the