Which Lewis electron-dot diagram represents a nitrogen atom in the ground state?

• A. N with five dots arranged as two pairs and one single dot
• B. N with five dots: one dot on each of three sides and a pair of dots on the fourth side
• C. N with five dots: one pair on one side and three single dots on the remaining sides
• D. N with six dots: two pairs and two single dots

Answer: (B)

Verified step by step guidance

1. Recall that a Lewis electron-dot diagram represents the valence electrons of an atom as dots placed around the chemical symbol.
2. Determine the number of valence electrons for nitrogen. Nitrogen is in group 15 of the periodic table, so it has 5 valence electrons.
3. Distribute the 5 valence electrons around the nitrogen symbol, placing one electron (dot) on each of the four sides before pairing any electrons, following Hund's rule to minimize electron repulsion.
4. Since nitrogen has 5 valence electrons, place one dot on three sides and a pair of dots on the fourth side, ensuring that no side has more than two electrons (a pair).
5. Verify that the total number of dots equals 5 and that the arrangement reflects the ground state electron configuration with unpaired electrons where possible.