Chapter 5 test Section 5.1 Flashcards - Quizlet The term that is used to label the energy levels of electrons is? S What letter is used to denote a spherical orbital? Dumbell All "p" orbital's are _____ shaped? 2n^2 What is the formula for the maximum number of electrons that can occupy a principal energy level? (Use "n" for the principal quantum number) Recommended textbook explanations