Sulfur's Valence Electrons and Orbital Filling

Steps:

• The valence shell is the outermost energy level (n=3), containing 3s²3p⁴ electrons, totaling 6 valence electrons.
• In the 3p subshell (three orbitals), 3p⁴ places one electron in each orbital first (Hund's rule), then pairs the fourth, leaving two singly occupied orbitals.
• Thus, 6 valence electrons and 2 unpaired electrons.

Why D is correct:

• Sulfur's group 16 position and 3s²3p⁴ configuration yield 6 valence electrons; Hund's rule dictates 2 unpaired electrons in p⁴.

Why the others are wrong:

• A: Valence electrons are 6, not 4; unpaired are 2, not 1.
• B: Valence electrons are 6, not 4.
• C: Unpaired electrons are 2, not 0.

Final answer: D