Question

1. what does hund’s rule (the bus rule) state? * before any orbital is doubly occupied... a. electrons pair before occupying empty orbitals. b. electrons occupy orbitals singly before pairing. c. electrons always prefer the s sublevel. d. protons determine electron placement.

Explanation:

Hund's Rule states that electrons occupy orbitals of the same energy (degenerate orbitals) singly first, with parallel spins, before pairing up. This maximizes the total spin and the stability of the atom.

Answer:

B. Electrons occupy orbitals singly before pairing.