In the Lewis dot structure of ammonia (NH_3), how many lone pairs are present on the nitrogen atom?

• A. 2
• B. 0
• C. 1
• D. 3

Answer: (C)

Verified step by step guidance

1. Identify the total number of valence electrons for nitrogen. Nitrogen is in group 15, so it has 5 valence electrons.
2. Recognize that each hydrogen atom contributes 1 valence electron, and there are 3 hydrogens, so total electrons from hydrogen are 3.
3. Combine the valence electrons: 5 (from N) + 3 (from H) = 8 valence electrons to be represented in the Lewis structure.
4. Draw the Lewis structure by placing nitrogen in the center and forming single bonds with each of the three hydrogen atoms. Each bond uses 2 electrons, so 3 bonds use 6 electrons.
5. Subtract the bonding electrons (6) from the total valence electrons (8) to find the remaining electrons, which are placed as lone pairs on nitrogen. The leftover 2 electrons form 1 lone pair on nitrogen.