Which of the following correctly states the number of valence electrons in H2S and provides the correct Lewis structure for the molecule?

• A. H2S has 4 valence electrons; the Lewis structure shows sulfur in the center with two single bonds to hydrogen and no lone pairs on sulfur.
• B. H2S has 8 valence electrons; the Lewis structure shows sulfur in the center with two single bonds to hydrogen and two lone pairs on sulfur.
• C. H2S has 10 valence electrons; the Lewis structure shows sulfur in the center with two double bonds to hydrogen and two lone pairs on sulfur.
• D. H2S has 6 valence electrons; the Lewis structure shows sulfur in the center with two single bonds to hydrogen and one lone pair on sulfur.

Answer: (B)

Verified step by step guidance

1. Determine the total number of valence electrons in H2S by adding the valence electrons of each atom: hydrogen has 1 valence electron each, and sulfur has 6 valence electrons. Use the formula: \(\text{Total valence electrons} = 2 \times 1 + 6\).
2. Draw the skeletal structure of H2S with sulfur as the central atom bonded to two hydrogen atoms using single bonds. Each single bond represents 2 electrons.
3. Subtract the electrons used in bonding from the total valence electrons to find the number of remaining electrons to be placed as lone pairs on sulfur.
4. Place the remaining electrons as lone pairs on the sulfur atom to complete its octet, ensuring sulfur has 8 electrons around it (including bonding and lone pairs).
5. Verify that all atoms have a complete valence shell: hydrogen atoms should have 2 electrons each (duet rule), and sulfur should have 8 electrons (octet rule). Confirm that the Lewis structure matches these criteria.