Which of the following are true statements?
a) The orbital energy of any atomic species depends on factors other than the principle quantum number n
b) Any given energy level in H is more stable than the same level in H+
c) The ionization energy of Li+ is about equal to the ionization level of He
d) The ionization energy of Li+ is much greater than the ionization energy of Li
e) Z eff of Li+ should be less than +3 but greater than +1