Ahydrogen-like ion is an ion containing only one electron. the energies of the electron in a hydrogen-like ion are given by en = −(2.18 × 10−18j) z2 (1/n2) where n is the principal quantum number and z is the atomic number of the element. calculate the ionization energy (in kj/mol) of the he+ ion.

For HE+, Z = 2, and you should assume ground state (n=1) for the outermost (only) electron. 
E = -2.81x10^-18 J (4) (1) E = -8.72x10^-18 J 
Now that's for one electron. Only enduring thing is that the reaction is requested in kJ/mol. 
E/mol = -8.72x10^-18J * 6.022x10^23/mol E/mol = 5.251x10^6 J/mol = 5251kJ/mol

The answer is 3,5g co

The answer is c) pyrite